21801104640 has 1728 divisors, whose sum is σ = 102852771840. Its totient is φ = 4299816960.

The previous prime is 21801104617. The next prime is 21801104651. The reversal of 21801104640 is 4640110812.

It is a happy number.

21801104640 is a `hidden beast` number, since 2 + 1 + 8 + 0 + 1 + 10 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 703261425 + ... + 703261455.

It is an arithmetic number, because the mean of its divisors is an integer number (59521280).

Almost surely, 2^21801104640 is an apocalyptic number.

21801104640 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 21801104640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51426385920).

21801104640 is an abundant number, since it is smaller than the sum of its proper divisors (81051667200).

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

21801104640 is a wasteful number, since it uses less digits than its factorization.

21801104640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The spelling of 21801104640 in words is "twenty-one billion, eight hundred one million, one hundred four thousand, six hundred forty".