21402642056400 has 180 divisors, whose sum is σ = 81025214456160. Its totient is φ = 5188519276800.

The previous prime is 21402642056377. The next prime is 21402642056407. The reversal of 21402642056400 is 465024620412.

21402642056400 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 2 + 6 + 4 + 2 + 0 + 5 + 640 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402642056407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 270195780 + ... + 270274979.

It is an arithmetic number, because the mean of its divisors is an integer number (450140080312).

Almost surely, 2^{21402642056400} is an apocalyptic number.

21402642056400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21402642056400 is an abundant number, since it is smaller than the sum of its proper divisors (59622572399760).

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

21402642056400 is a wasteful number, since it uses less digits than its factorization.

21402642056400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540470794 (or 540470780 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

Adding to 21402642056400 its reverse (465024620412), we get a palindrome (21867666676812).

The spelling of 21402642056400 in words is "twenty-one trillion, four hundred two billion, six hundred forty-two million, fifty-six thousand, four hundred".