21225163508640 has 1152 divisors, whose sum is σ = 94540577144832. Its totient is φ = 4208105226240.

The previous prime is 21225163508639. The next prime is 21225163508669. The reversal of 21225163508640 is 4680536152212.

21225163508640 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 5 + 1 + 635 + 0 + 8 + 6 + 4 + 0 = 666.

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 (23) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1454667745 + ... + 1454682335.

It is an arithmetic number, because the mean of its divisors is an integer number (82066473216).

Almost surely, 2^{21225163508640} is an apocalyptic number.

21225163508640 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 21225163508640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47270288572416).

21225163508640 is an abundant number, since it is smaller than the sum of its proper divisors (73315413636192).

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

21225163508640 is a wasteful number, since it uses less digits than its factorization.

21225163508640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15302 (or 15291 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 21225163508640 in words is "twenty-one trillion, two hundred twenty-five billion, one hundred sixty-three million, five hundred eight thousand, six hundred forty".