21554977931136 has 640 divisors, whose sum is σ = 69633805903200. Its totient is φ = 6579520192512.

The previous prime is 21554977931077. The next prime is 21554977931143. The reversal of 21554977931136 is 63113977945512.

21554977931136 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 497 + 7 + 9 + 3 + 1 + 136 = 666.

It is a super-2 number, since 2×21554977931136² (a number of 27 digits) contains 22 as substring.

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 79 ways as a sum of consecutive naturals, for example, 9784373811 + ... + 9784376013.

Almost surely, 2^{21554977931136} is an apocalyptic number.

21554977931136 is a gapful number since it is divisible by the number (26) 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 21554977931136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34816902951600).

21554977931136 is an abundant number, since it is smaller than the sum of its proper divisors (48078827972064).

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

21554977931136 is a wasteful number, since it uses less digits than its factorization.

21554977931136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2788 (or 2767 counting only the distinct ones).

The product of its digits is 42865200, while the sum is 63.

The spelling of 21554977931136 in words is "twenty-one trillion, five hundred fifty-four billion, nine hundred seventy-seven million, nine hundred thirty-one thousand, one hundred thirty-six".