10521491921 has 8 divisors (see below), whose sum is σ = 10629864960. Its totient is φ = 10413238752.

The previous prime is 10521491881. The next prime is 10521491951. The reversal of 10521491921 is 12919412501.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10521491921 - 2⁶ = 10521491857 is a prime.

It is a super-5 number, since 5×10521491921⁵ (a number of 51 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10521491951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152141 + ... + 210213.

It is an arithmetic number, because the mean of its divisors is an integer number (1328733120).

Almost surely, 2^10521491921 is an apocalyptic number.

It is an amenable number.

10521491921 is a deficient number, since it is larger than the sum of its proper divisors (108373039).

10521491921 is a wasteful number, since it uses less digits than its factorization.

10521491921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59935.

The product of its (nonzero) digits is 6480, while the sum is 35.

The spelling of 10521491921 in words is "ten billion, five hundred twenty-one million, four hundred ninety-one thousand, nine hundred twenty-one".