921690051 has 4 divisors (see below), whose sum is σ = 1228920072. Its totient is φ = 614460032.

The previous prime is 921690031. The next prime is 921690061. The reversal of 921690051 is 150096129.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 921690051 - 2²⁶ = 854581187 is a prime.

It is a super-2 number, since 2×921690051² = 1699025100224765202, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 921689994 and 921690021.

It is not an unprimeable number, because it can be changed into a prime (921690001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153615006 + ... + 153615011.

It is an arithmetic number, because the mean of its divisors is an integer number (307230018).

Almost surely, 2^921690051 is an apocalyptic number.

921690051 is a deficient number, since it is larger than the sum of its proper divisors (307230021).

921690051 is a wasteful number, since it uses less digits than its factorization.

921690051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307230020.

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 921690051 is about 30359.3486590210. The cubic root of 921690051 is about 973.1840143458.

The spelling of 921690051 in words is "nine hundred twenty-one million, six hundred ninety thousand, fifty-one".