921571399 has 16 divisors (see below), whose sum is σ = 1093827328. Its totient is φ = 760015872.

The previous prime is 921571393. The next prime is 921571423. The reversal of 921571399 is 993175129.

921571399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 921571399 - 2²⁵ = 888016967 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 (921571393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2682 + ... + 43015.

It is an arithmetic number, because the mean of its divisors is an integer number (68364208).

Almost surely, 2^921571399 is an apocalyptic number.

921571399 is a deficient number, since it is larger than the sum of its proper divisors (172255929).

921571399 is a wasteful number, since it uses less digits than its factorization.

921571399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45814.

The product of its digits is 153090, while the sum is 46.

The square root of 921571399 is about 30357.3944698816. The cubic root of 921571399 is about 973.1422522282.

The spelling of 921571399 in words is "nine hundred twenty-one million, five hundred seventy-one thousand, three hundred ninety-nine".