921379517 has 4 divisors (see below), whose sum is σ = 961439520. Its totient is φ = 881319516.

The previous prime is 921379477. The next prime is 921379541. The reversal of 921379517 is 715973129.

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 a cyclic number.

It is not a de Polignac number, because 921379517 - 2²⁴ = 904602301 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 (921379717) 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, 20029967 + ... + 20030012.

It is an arithmetic number, because the mean of its divisors is an integer number (240359880).

Almost surely, 2^921379517 is an apocalyptic number.

It is an amenable number.

921379517 is a deficient number, since it is larger than the sum of its proper divisors (40060003).

921379517 is a wasteful number, since it uses less digits than its factorization.

921379517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40060002.

The product of its digits is 119070, while the sum is 44.

The square root of 921379517 is about 30354.2339221401. The cubic root of 921379517 is about 973.0747076541.

The spelling of 921379517 in words is "nine hundred twenty-one million, three hundred seventy-nine thousand, five hundred seventeen".