81157602836 has 24 divisors (see below), whose sum is σ = 142737514920. Its totient is φ = 40375706112.

The previous prime is 81157602833. The next prime is 81157602847. The reversal of 81157602836 is 63820675118.

It can be written as a sum of positive squares in 4 ways, for example, as 4328850436 + 76828752400 = 65794^2 + 277180^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81157602833) 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, 1301360 + ... + 1362296.

It is an arithmetic number, because the mean of its divisors is an integer number (5947396455).

Almost surely, 2^81157602836 is an apocalyptic number.

It is an amenable number.

81157602836 is a deficient number, since it is larger than the sum of its proper divisors (61579912084).

81157602836 is a wasteful number, since it uses less digits than its factorization.

81157602836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62603 (or 62601 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 81157602836 in words is "eighty-one billion, one hundred fifty-seven million, six hundred two thousand, eight hundred thirty-six".