81901052352 has 504 divisors, whose sum is σ = 279893792256. Its totient is φ = 22824861696.

The previous prime is 81901052287. The next prime is 81901052369. The reversal of 81901052352 is 25325010918.

81901052352 is a `hidden beast` number, since 81 + 9 + 0 + 1 + 0 + 523 + 52 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 261664548 + ... + 261664860.

Almost surely, 2^81901052352 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81901052352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139946896128).

81901052352 is an abundant number, since it is smaller than the sum of its proper divisors (197992739904).

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

81901052352 is a wasteful number, since it uses less digits than its factorization.

81901052352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545 (or 525 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The spelling of 81901052352 in words is "eighty-one billion, nine hundred one million, fifty-two thousand, three hundred fifty-two".