921561969 has 4 divisors (see below), whose sum is σ = 1228749296. Its totient is φ = 614374644.

The previous prime is 921561967. The next prime is 921562009. The reversal of 921561969 is 969165129.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 921561969 - 2¹ = 921561967 is a prime.

It is a super-2 number, since 2×921561969² = 1698552925414313922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921561967) 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, 153593659 + ... + 153593664.

It is an arithmetic number, because the mean of its divisors is an integer number (307187324).

Almost surely, 2^921561969 is an apocalyptic number.

It is an amenable number.

921561969 is a deficient number, since it is larger than the sum of its proper divisors (307187327).

921561969 is a wasteful number, since it uses less digits than its factorization.

921561969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307187326.

The product of its digits is 262440, while the sum is 48.

The square root of 921561969 is about 30357.2391531246. The cubic root of 921561969 is about 973.1389329835.

The spelling of 921561969 in words is "nine hundred twenty-one million, five hundred sixty-one thousand, nine hundred sixty-nine".