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81797947 = 7111062311
BaseRepresentation
bin1001110000000…
…10001100111011
312200220202200121
410320002030323
5131420013242
612041114111
72012161660
oct470021473
9180822617
1081797947
114219a010
1223488937
1313c3c86a
14ac13a67
1572ab667
hex4e0233b

81797947 has 8 divisors (see below), whose sum is σ = 101981952. Its totient is φ = 63738600.

The previous prime is 81797941. The next prime is 81797953. The reversal of 81797947 is 74979718.

It is an interprime number because it is at equal distance from previous prime (81797941) and next prime (81797953).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81797947 - 23 = 81797939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81797894 and 81797903.

It is not an unprimeable number, because it can be changed into a prime (81797941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 531079 + ... + 531232.

It is an arithmetic number, because the mean of its divisors is an integer number (12747744).

Almost surely, 281797947 is an apocalyptic number.

81797947 is a deficient number, since it is larger than the sum of its proper divisors (20184005).

81797947 is a wasteful number, since it uses less digits than its factorization.

81797947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062329.

The product of its digits is 889056, while the sum is 52.

The square root of 81797947 is about 9044.2217465075. The cubic root of 81797947 is about 434.0910195105.

The spelling of 81797947 in words is "eighty-one million, seven hundred ninety-seven thousand, nine hundred forty-seven".

Divisors: 1 7 11 77 1062311 7436177 11685421 81797947