81603076590 has 144 divisors (see below), whose sum is σ = 255949070832. Its totient is φ = 18652104576.

The previous prime is 81603076549. The next prime is 81603076601. The reversal of 81603076590 is 9567030618.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 223599 + ... + 461738.

It is an arithmetic number, because the mean of its divisors is an integer number (1777424103).

Almost surely, 2^81603076590 is an apocalyptic number.

81603076590 is an abundant number, since it is smaller than the sum of its proper divisors (174345994242).

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

81603076590 is a wasteful number, since it uses less digits than its factorization.

81603076590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685373 (or 685354 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 81603076590 in words is "eighty-one billion, six hundred three million, seventy-six thousand, five hundred ninety".