20957899 has 8 divisors (see below), whose sum is σ = 22378752. Its totient is φ = 19579560.

The previous prime is 20957869. The next prime is 20957903. The reversal of 20957899 is 99875902.

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

It is a cyclic number.

It is not a de Polignac number, because 20957899 - 2²¹ = 18860747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20957819) 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, 9607 + ... + 11584.

It is an arithmetic number, because the mean of its divisors is an integer number (2797344).

Almost surely, 2^20957899 is an apocalyptic number.

20957899 is a deficient number, since it is larger than the sum of its proper divisors (1420853).

20957899 is a wasteful number, since it uses less digits than its factorization.

20957899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21257.

The product of its (nonzero) digits is 408240, while the sum is 49.

The square root of 20957899 is about 4577.9797946256. The cubic root of 20957899 is about 275.7079237093.

The spelling of 20957899 in words is "twenty million, nine hundred fifty-seven thousand, eight hundred ninety-nine".