20649610800 has 480 divisors, whose sum is σ = 90462543360. Its totient is φ = 4356633600.

The previous prime is 20649610783. The next prime is 20649610823. The reversal of 20649610800 is 801694602.

20649610800 is a `hidden beast` number, since 2 + 0 + 649 + 6 + 1 + 0 + 8 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 972295 + ... + 993305.

It is an arithmetic number, because the mean of its divisors is an integer number (188463632).

Almost surely, 2^20649610800 is an apocalyptic number.

20649610800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20649610800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45231271680).

20649610800 is an abundant number, since it is smaller than the sum of its proper divisors (69812932560).

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

20649610800 is a wasteful number, since it uses less digits than its factorization.

20649610800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21058 (or 21041 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 20649610800 in words is "twenty billion, six hundred forty-nine million, six hundred ten thousand, eight hundred".