21077808768 has 512 divisors, whose sum is σ = 69400800000. Its totient is φ = 6267469824.

The previous prime is 21077808767. The next prime is 21077808781. The reversal of 21077808768 is 86780877012.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (21077808767) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 151638843 + ... + 151638981.

Almost surely, 2^21077808768 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 21077808768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34700400000).

21077808768 is an abundant number, since it is smaller than the sum of its proper divisors (48322991232).

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

21077808768 is a wasteful number, since it uses less digits than its factorization.

21077808768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 2107392, while the sum is 54.

The spelling of 21077808768 in words is "twenty-one billion, seventy-seven million, eight hundred eight thousand, seven hundred sixty-eight".