21376638771840 has 3072 divisors, whose sum is σ = 92478731304960. Its totient is φ = 4658135040000.

The previous prime is 21376638771779. The next prime is 21376638771899. The reversal of 21376638771840 is 4817783667312.

21376638771840 is a `hidden beast` number, since 2 + 1 + 3 + 76 + 6 + 387 + 7 + 184 + 0 = 666.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 118102976550 + ... + 118102976730.

It is an arithmetic number, because the mean of its divisors is an integer number (30103753680).

Almost surely, 2^{21376638771840} is an apocalyptic number.

21376638771840 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 21376638771840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46239365652480).

21376638771840 is an abundant number, since it is smaller than the sum of its proper divisors (71102092533120).

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

21376638771840 is a wasteful number, since it uses less digits than its factorization.

21376638771840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 381 counting only the distinct ones).

The product of its (nonzero) digits is 56899584, while the sum is 63.

The spelling of 21376638771840 in words is "twenty-one trillion, three hundred seventy-six billion, six hundred thirty-eight million, seven hundred seventy-one thousand, eight hundred forty".