81465957 has 12 divisors (see below), whose sum is σ = 117971724. Its totient is φ = 54172800.

The previous prime is 81465947. The next prime is 81465983. The reversal of 81465957 is 75956418.

It can be written as a sum of positive squares in 2 ways, for example, as 46253601 + 35212356 = 6801^2 + 5934^2 .

It is not a de Polignac number, because 81465957 - 2⁷ = 81465829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81465907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7678 + ... + 14895.

It is an arithmetic number, because the mean of its divisors is an integer number (9830977).

Almost surely, 2^81465957 is an apocalyptic number.

It is an amenable number.

81465957 is a deficient number, since it is larger than the sum of its proper divisors (36505767).

81465957 is a wasteful number, since it uses less digits than its factorization.

81465957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22980 (or 22977 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 81465957 is about 9025.8493783134. The cubic root of 81465957 is about 433.5029473425.

The spelling of 81465957 in words is "eighty-one million, four hundred sixty-five thousand, nine hundred fifty-seven".