21455692558272 has 672 divisors, whose sum is σ = 76683864391680. Its totient is φ = 5818996039680.

The previous prime is 21455692558247. The next prime is 21455692558277. The reversal of 21455692558272 is 27285529655412.

21455692558272 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 5 + 6 + 9 + 2 + 558 + 2 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455692558277) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 165081729 + ... + 165211647.

It is an arithmetic number, because the mean of its divisors is an integer number (114112893440).

Almost surely, 2^{21455692558272} 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 21455692558272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38341932195840).

21455692558272 is an abundant number, since it is smaller than the sum of its proper divisors (55228171833408).

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

21455692558272 is a wasteful number, since it uses less digits than its factorization.

21455692558272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130031 (or 130009 counting only the distinct ones).

The product of its digits is 120960000, while the sum is 63.

The spelling of 21455692558272 in words is "twenty-one trillion, four hundred fifty-five billion, six hundred ninety-two million, five hundred fifty-eight thousand, two hundred seventy-two".