81900292152 has 64 divisors (see below), whose sum is σ = 234399755520. Its totient is φ = 23360191488.

The previous prime is 81900292121. The next prime is 81900292169. The reversal of 81900292152 is 25129200918.

It is a super-2 number, since 2×81900292152² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81900292152.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 316633 + ... + 513864.

It is an arithmetic number, because the mean of its divisors is an integer number (3662496180).

Almost surely, 2^81900292152 is an apocalyptic number.

It is an amenable number.

81900292152 is an abundant number, since it is smaller than the sum of its proper divisors (152499463368).

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

81900292152 is a wasteful number, since it uses less digits than its factorization.

81900292152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831100 (or 831096 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 39.

The spelling of 81900292152 in words is "eighty-one billion, nine hundred million, two hundred ninety-two thousand, one hundred fifty-two".