81860631 has 4 divisors (see below), whose sum is σ = 109147512. Its totient is φ = 54573752.

The previous prime is 81860599. The next prime is 81860663. The reversal of 81860631 is 13606818.

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

It is an interprime number because it is at equal distance from previous prime (81860599) and next prime (81860663).

It is a cyclic number.

It is not a de Polignac number, because 81860631 - 2⁵ = 81860599 is a prime.

It is a super-2 number, since 2×81860631² = 13402325815436322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81860592 and 81860601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81861631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13643436 + ... + 13643441.

It is an arithmetic number, because the mean of its divisors is an integer number (27286878).

Almost surely, 2^81860631 is an apocalyptic number.

81860631 is a deficient number, since it is larger than the sum of its proper divisors (27286881).

81860631 is a wasteful number, since it uses less digits than its factorization.

81860631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27286880.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 81860631 is about 9047.6864998739. The cubic root of 81860631 is about 434.2018764643.

The spelling of 81860631 in words is "eighty-one million, eight hundred sixty thousand, six hundred thirty-one".