20831397 has 8 divisors (see below), whose sum is σ = 27907680. Its totient is φ = 13821360.

The previous prime is 20831323. The next prime is 20831533. The reversal of 20831397 is 79313802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20831397 - 2⁷ = 20831269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20832397) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15822 + ... + 17087.

It is an arithmetic number, because the mean of its divisors is an integer number (3488460).

Almost surely, 2^20831397 is an apocalyptic number.

It is an amenable number.

20831397 is a deficient number, since it is larger than the sum of its proper divisors (7076283).

20831397 is a wasteful number, since it uses less digits than its factorization.

20831397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33123.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 20831397 is about 4564.1425262584. The cubic root of 20831397 is about 275.1520789680.

The spelling of 20831397 in words is "twenty million, eight hundred thirty-one thousand, three hundred ninety-seven".