21136740563808 has 336 divisors, whose sum is σ = 68191986554496. Its totient is φ = 6417223004160.

The previous prime is 21136740563761. The next prime is 21136740563821. The reversal of 21136740563808 is 80836504763112.

21136740563808 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 6 + 74 + 0 + 563 + 8 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 11434210 + ... + 13153502.

It is an arithmetic number, because the mean of its divisors is an integer number (202952340936).

Almost surely, 2^{21136740563808} 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 21136740563808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34095993277248).

21136740563808 is an abundant number, since it is smaller than the sum of its proper divisors (47055245990688).

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

21136740563808 is a wasteful number, since it uses less digits than its factorization.

21136740563808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1719369 (or 1719346 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 54.

The spelling of 21136740563808 in words is "twenty-one trillion, one hundred thirty-six billion, seven hundred forty million, five hundred sixty-three thousand, eight hundred eight".