81507492004 has 24 divisors (see below), whose sum is σ = 143971196600. Its totient is φ = 40372992000.

The previous prime is 81507491999. The next prime is 81507492037. The reversal of 81507492004 is 40029470518.

It can be written as a sum of positive squares in 4 ways, for example, as 13537787904 + 67969704100 = 116352^2 + 260710^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3384004 + ... + 3408004.

Almost surely, 2^81507492004 is an apocalyptic number.

It is an amenable number.

81507492004 is a deficient number, since it is larger than the sum of its proper divisors (62463704596).

81507492004 is a wasteful number, since it uses less digits than its factorization.

81507492004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31903 (or 31901 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 81507492004 in words is "eighty-one billion, five hundred seven million, four hundred ninety-two thousand, four".