21231635775840 has 1152 divisors, whose sum is σ = 90618323927040. Its totient is φ = 4419077160960.

The previous prime is 21231635775769. The next prime is 21231635775841. The reversal of 21231635775840 is 4857753613212.

21231635775840 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 1 + 6 + 3 + 57 + 7 + 584 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231635775841) 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 191 ways as a sum of consecutive naturals, for example, 5104983681 + ... + 5104987839.

It is an arithmetic number, because the mean of its divisors is an integer number (78661739520).

Almost surely, 2^{21231635775840} is an apocalyptic number.

21231635775840 is a gapful number since it is divisible by the number (20) 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 21231635775840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45309161963520).

21231635775840 is an abundant number, since it is smaller than the sum of its proper divisors (69386688151200).

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

21231635775840 is a wasteful number, since it uses less digits than its factorization.

21231635775840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4297 (or 4224 counting only the distinct ones).

The product of its (nonzero) digits is 8467200, while the sum is 54.

The spelling of 21231635775840 in words is "twenty-one trillion, two hundred thirty-one billion, six hundred thirty-five million, seven hundred seventy-five thousand, eight hundred forty".