91521355994000 has 80 divisors (see below), whose sum is σ = 227279683268976. Its totient is φ = 35619122304000.

The previous prime is 91521355993987. The next prime is 91521355994009. The reversal of 91521355994000 is 49955312519.

It can be written as a sum of positive squares in 8 ways, for example, as 31736727863296 + 59784628130704 = 5633536^2 + 7732052^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (91521355994009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 618313541 + ... + 618461540.

Almost surely, 2^{91521355994000} is an apocalyptic number.

It is an amenable number.

91521355994000 is an abundant number, since it is smaller than the sum of its proper divisors (135758327274976).

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

91521355994000 is a wasteful number, since it uses less digits than its factorization.

91521355994000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1236775141 (or 1236775125 counting only the distinct ones).

The product of its (nonzero) digits is 2187000, while the sum is 53.

The spelling of 91521355994000 in words is "ninety-one trillion, five hundred twenty-one billion, three hundred fifty-five million, nine hundred ninety-four thousand".