921621133 has 4 divisors (see below), whose sum is σ = 921843900. Its totient is φ = 921398368.

The previous prime is 921621097. The next prime is 921621137. The reversal of 921621133 is 331126129.

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

It can be written as a sum of positive squares in 2 ways, for example, as 553096324 + 368524809 = 23518^2 + 19197^2 .

It is a cyclic number.

It is not a de Polignac number, because 921621133 - 2²⁵ = 888066701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921621137) 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, 105058 + ... + 113491.

It is an arithmetic number, because the mean of its divisors is an integer number (230460975).

Almost surely, 2^921621133 is an apocalyptic number.

It is an amenable number.

921621133 is a deficient number, since it is larger than the sum of its proper divisors (222767).

921621133 is a wasteful number, since it uses less digits than its factorization.

921621133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222766.

The product of its digits is 1944, while the sum is 28.

The square root of 921621133 is about 30358.2136002763. The cubic root of 921621133 is about 973.1597576131.

The spelling of 921621133 in words is "nine hundred twenty-one million, six hundred twenty-one thousand, one hundred thirty-three".