20904677640 has 1536 divisors, whose sum is σ = 97820835840. Its totient is φ = 3881779200.

The previous prime is 20904677639. The next prime is 20904677653. The reversal of 20904677640 is 4677640902.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 394427854 + ... + 394427906.

It is an arithmetic number, because the mean of its divisors is an integer number (63685440).

Almost surely, 2^20904677640 is an apocalyptic number.

20904677640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is a pronic number, being equal to 144584×144585.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20904677640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48910417920).

20904677640 is an abundant number, since it is smaller than the sum of its proper divisors (76916158200).

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

20904677640 is a wasteful number, since it uses less digits than its factorization.

20904677640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 20904677640 in words is "twenty billion, nine hundred four million, six hundred seventy-seven thousand, six hundred forty".