81574263768 has 32 divisors (see below), whose sum is σ = 215931875760. Its totient is φ = 25591925760.

The previous prime is 81574263761. The next prime is 81574263781. The reversal of 81574263768 is 86736247518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81574263761) 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, 99968053 + ... + 99968868.

Almost surely, 2^81574263768 is an apocalyptic number.

It is an amenable number.

81574263768 is an abundant number, since it is smaller than the sum of its proper divisors (134357611992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81574263768 is a wasteful number, since it uses less digits than its factorization.

81574263768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199936947 (or 199936943 counting only the distinct ones).

The product of its digits is 13547520, while the sum is 57.

The spelling of 81574263768 in words is "eighty-one billion, five hundred seventy-four million, two hundred sixty-three thousand, seven hundred sixty-eight".