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81577000791 = 321113456713879
BaseRepresentation
bin100101111111001011…
…1100011111101010111
321210120020112000101200
41023332113203331113
52314032203011131
6101250450123543
75615361031356
oct1137627437527
9253506460350
1081577000791
11316620aa120
1213987b805b3
137900a77290
143d3c3a399d
1521c6b782e6
hex12fe5e3f57

81577000791 has 48 divisors (see below), whose sum is σ = 138473986560. Its totient is φ = 45624202560.

The previous prime is 81577000763. The next prime is 81577000801. The reversal of 81577000791 is 19700077518.

It is a happy number.

81577000791 is a `hidden beast` number, since 8 + 1 + 577 + 0 + 0 + 0 + 79 + 1 = 666.

It is not a de Polignac number, because 81577000791 - 211 = 81576998743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81577000391) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5870790 + ... + 5884668.

It is an arithmetic number, because the mean of its divisors is an integer number (2884874720).

Almost surely, 281577000791 is an apocalyptic number.

81577000791 is the 152669-th nonagonal number.

81577000791 is a deficient number, since it is larger than the sum of its proper divisors (56896985769).

81577000791 is a wasteful number, since it uses less digits than its factorization.

81577000791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18476 (or 18473 counting only the distinct ones).

The product of its (nonzero) digits is 123480, while the sum is 45.

The spelling of 81577000791 in words is "eighty-one billion, five hundred seventy-seven million, seven hundred ninety-one", and thus it is an aban number.

Divisors: 1 3 9 11 13 33 39 99 117 143 429 1287 4567 13701 13879 41103 41637 50237 59371 124911 150711 152669 178113 180427 452133 458007 534339 541281 653081 1374021 1623843 1959243 1984697 5877729 5954091 17862273 63385393 190156179 570468537 697239323 824010109 2091717969 2472030327 6275153907 7416090981 9064111199 27192333597 81577000791