21405455321312 has 192 divisors, whose sum is σ = 46385313085440. Its totient is φ = 9685204992000.

The previous prime is 21405455321303. The next prime is 21405455321333. The reversal of 21405455321312 is 21312355450412.

It is a super-2 number, since 2×21405455321312² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 1878819488 + ... + 1878830880.

It is an arithmetic number, because the mean of its divisors is an integer number (241590172320).

Almost surely, 2^{21405455321312} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21405455321312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23192656542720).

21405455321312 is an abundant number, since it is smaller than the sum of its proper divisors (24979857764128).

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

21405455321312 is a wasteful number, since it uses less digits than its factorization.

21405455321312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12737 (or 12729 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 38.

The spelling of 21405455321312 in words is "twenty-one trillion, four hundred five billion, four hundred fifty-five million, three hundred twenty-one thousand, three hundred twelve".