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81541 = 731117
BaseRepresentation
bin10011111010000101
311010212001
4103322011
510102131
61425301
7456505
oct237205
9133761
1081541
1156299
123b231
132b165
1421a05
1519261
hex13e85

81541 has 4 divisors (see below), whose sum is σ = 82732. Its totient is φ = 80352.

The previous prime is 81533. The next prime is 81547. The reversal of 81541 is 14518.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21025 + 60516 = 145^2 + 246^2 .

It is a cyclic number.

It is not a de Polignac number, because 81541 - 23 = 81533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 486 + ... + 631.

It is an arithmetic number, because the mean of its divisors is an integer number (20683).

281541 is an apocalyptic number.

It is an amenable number.

81541 is a deficient number, since it is larger than the sum of its proper divisors (1191).

81541 is a wasteful number, since it uses less digits than its factorization.

81541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190.

The product of its digits is 160, while the sum is 19.

The square root of 81541 is about 285.5538478116. The cubic root of 81541 is about 43.3636014696.

The spelling of 81541 in words is "eighty-one thousand, five hundred forty-one".

Divisors: 1 73 1117 81541