20904355173 has 16 divisors (see below), whose sum is σ = 30046854656. Its totient is φ = 12851213760.

The previous prime is 20904355139. The next prime is 20904355211. The reversal of 20904355173 is 37155340902.

It is a happy number.

It is not a de Polignac number, because 20904355173 - 2⁸ = 20904354917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20904355973) 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, 231790 + ... + 309087.

It is an arithmetic number, because the mean of its divisors is an integer number (1877928416).

Almost surely, 2^20904355173 is an apocalyptic number.

It is an amenable number.

20904355173 is a deficient number, since it is larger than the sum of its proper divisors (9142499483).

20904355173 is a wasteful number, since it uses less digits than its factorization.

20904355173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541884.

The product of its (nonzero) digits is 113400, while the sum is 39.

The spelling of 20904355173 in words is "twenty billion, nine hundred four million, three hundred fifty-five thousand, one hundred seventy-three".