20957739 has 16 divisors (see below), whose sum is σ = 30668544. Its totient is φ = 12624800.

The previous prime is 20957731. The next prime is 20957777. The reversal of 20957739 is 93775902.

It is a cyclic number.

It is not a de Polignac number, because 20957739 - 2³ = 20957731 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20957739.

It is not an unprimeable number, because it can be changed into a prime (20957731) 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, 3874 + ... + 7544.

It is an arithmetic number, because the mean of its divisors is an integer number (1916784).

Almost surely, 2^20957739 is an apocalyptic number.

20957739 is a deficient number, since it is larger than the sum of its proper divisors (9710805).

20957739 is a wasteful number, since it uses less digits than its factorization.

20957739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3858.

The product of its (nonzero) digits is 119070, while the sum is 42.

The square root of 20957739 is about 4577.9623196352. The cubic root of 20957739 is about 275.7072220903.

It can be divided in two parts, 20 and 957739, that added together give a palindrome (957759).

The spelling of 20957739 in words is "twenty million, nine hundred fifty-seven thousand, seven hundred thirty-nine".