81178397239400 has 96 divisors (see below), whose sum is σ = 196294531584000. Its totient is φ = 31193833432320.

The previous prime is 81178397239367. The next prime is 81178397239447. The reversal of 81178397239400 is 493279387118.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68846120 + ... + 70015319.

It is an arithmetic number, because the mean of its divisors is an integer number (2044734704000).

Almost surely, 2^{81178397239400} is an apocalyptic number.

It is an amenable number.

81178397239400 is an abundant number, since it is smaller than the sum of its proper divisors (115116134344600).

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

81178397239400 is a wasteful number, since it uses less digits than its factorization.

81178397239400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138861571 (or 138861562 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 62.

The spelling of 81178397239400 in words is "eighty-one trillion, one hundred seventy-eight billion, three hundred ninety-seven million, two hundred thirty-nine thousand, four hundred".