81457431790 has 64 divisors (see below), whose sum is σ = 175344906240. Its totient is φ = 26657061120.

The previous prime is 81457431773. The next prime is 81457431799. The reversal of 81457431790 is 9713475418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81457431799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 98700 + ... + 415519.

It is an arithmetic number, because the mean of its divisors is an integer number (2739764160).

Almost surely, 2^81457431790 is an apocalyptic number.

81457431790 is an abundant number, since it is smaller than the sum of its proper divisors (93887474450).

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

81457431790 is a wasteful number, since it uses less digits than its factorization.

81457431790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514337.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 81457431790 in words is "eighty-one billion, four hundred fifty-seven million, four hundred thirty-one thousand, seven hundred ninety".