20957169 has 16 divisors (see below), whose sum is σ = 29131200. Its totient is φ = 13384896.

The previous prime is 20957161. The next prime is 20957173. The reversal of 20957169 is 96175902.

It is not a de Polignac number, because 20957169 - 2³ = 20957161 is a prime.

It is a super-2 number, since 2×20957169² = 878405864989122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20957161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11227 + ... + 12959.

It is an arithmetic number, because the mean of its divisors is an integer number (1820700).

Almost surely, 2^20957169 is an apocalyptic number.

20957169 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20957169 is a deficient number, since it is larger than the sum of its proper divisors (8174031).

20957169 is a wasteful number, since it uses less digits than its factorization.

20957169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1904.

The product of its (nonzero) digits is 34020, while the sum is 39.

The square root of 20957169 is about 4577.9000644400. The cubic root of 20957169 is about 275.7047225436.

The spelling of 20957169 in words is "twenty million, nine hundred fifty-seven thousand, one hundred sixty-nine".