20939731904 has 224 divisors, whose sum is σ = 52509090816. Its totient is φ = 8065474560.

The previous prime is 20939731877. The next prime is 20939731927. The reversal of 20939731904 is 40913793902.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a super-2 number, since 2×20939731904² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40191164 + ... + 40191684.

It is an arithmetic number, because the mean of its divisors is an integer number (234415584).

Almost surely, 2^20939731904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20939731904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26254545408).

20939731904 is an abundant number, since it is smaller than the sum of its proper divisors (31569358912).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20939731904 is a wasteful number, since it uses less digits than its factorization.

20939731904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 367416, while the sum is 47.

The spelling of 20939731904 in words is "twenty billion, nine hundred thirty-nine million, seven hundred thirty-one thousand, nine hundred four".