81623315685 has 16 divisors (see below), whose sum is σ = 130603239360. Its totient is φ = 43530456960.

The previous prime is 81623315647. The next prime is 81623315689. The reversal of 81623315685 is 58651332618.

It is not a de Polignac number, because 81623315685 - 2⁸ = 81623315429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81623315689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254865 + ... + 477705.

It is an arithmetic number, because the mean of its divisors is an integer number (8162702460).

Almost surely, 2^81623315685 is an apocalyptic number.

It is an amenable number.

81623315685 is a deficient number, since it is larger than the sum of its proper divisors (48979923675).

81623315685 is a wasteful number, since it uses less digits than its factorization.

81623315685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247268.

The product of its digits is 1036800, while the sum is 48.

The spelling of 81623315685 in words is "eighty-one billion, six hundred twenty-three million, three hundred fifteen thousand, six hundred eighty-five".