20761131904 has 64 divisors (see below), whose sum is σ = 41666796000. Its totient is φ = 10303856640.

The previous prime is 20761131899. The next prime is 20761131967. The reversal of 20761131904 is 40913116702.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 20761131904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15715564 + ... + 15716884.

Almost surely, 2^20761131904 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 20761131904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20833398000).

20761131904 is an abundant number, since it is smaller than the sum of its proper divisors (20905664096).

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

20761131904 is a wasteful number, since it uses less digits than its factorization.

20761131904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151 (or 2139 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 34.

The spelling of 20761131904 in words is "twenty billion, seven hundred sixty-one million, one hundred thirty-one thousand, nine hundred four".