20904557942739 has 16 divisors (see below), whose sum is σ = 27878027975424. Its totient is φ = 13933730210400.

The previous prime is 20904557942729. The next prime is 20904557942747. The reversal of 20904557942739 is 93724975540902.

It is a happy number.

It is not a de Polignac number, because 20904557942739 - 2⁸ = 20904557942483 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20904557942739.

It is not an unprimeable number, because it can be changed into a prime (20904557942729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 524390122 + ... + 524429984.

It is an arithmetic number, because the mean of its divisors is an integer number (1742376748464).

Almost surely, 2^{20904557942739} is an apocalyptic number.

20904557942739 is a deficient number, since it is larger than the sum of its proper divisors (6973470032685).

20904557942739 is a wasteful number, since it uses less digits than its factorization.

20904557942739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68618.

The product of its (nonzero) digits is 171460800, while the sum is 66.

The spelling of 20904557942739 in words is "twenty trillion, nine hundred four billion, five hundred fifty-seven million, nine hundred forty-two thousand, seven hundred thirty-nine".