81900090846 has 64 divisors (see below), whose sum is σ = 208751400960. Its totient is φ = 23315519520.

The previous prime is 81900090841. The next prime is 81900090887. The reversal of 81900090846 is 64809000918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81900090841) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 286390 + ... + 495801.

It is an arithmetic number, because the mean of its divisors is an integer number (3261740640).

Almost surely, 2^81900090846 is an apocalyptic number.

81900090846 is an abundant number, since it is smaller than the sum of its proper divisors (126851310114).

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

81900090846 is a wasteful number, since it uses less digits than its factorization.

81900090846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782486 (or 782480 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 81900090846 in words is "eighty-one billion, nine hundred million, ninety thousand, eight hundred forty-six".