21139677751968 has 144 divisors (see below), whose sum is σ = 60227702720640. Its totient is φ = 7033473280512.

The previous prime is 21139677751961. The next prime is 21139677751987. The reversal of 21139677751968 is 86915777693112.

21139677751968 is a `hidden beast` number, since 2 + 1 + 1 + 39 + 6 + 7 + 77 + 519 + 6 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-3 number, since 3×21139677751968³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 21139677751896 and 21139677751905.

It is not an unprimeable number, because it can be changed into a prime (21139677751961) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 343374373 + ... + 343435931.

It is an arithmetic number, because the mean of its divisors is an integer number (418247935560).

Almost surely, 2^{21139677751968} is an apocalyptic number.

It is an amenable number.

21139677751968 is an abundant number, since it is smaller than the sum of its proper divisors (39088024968672).

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

21139677751968 is a wasteful number, since it uses less digits than its factorization.

21139677751968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63771 (or 63760 counting only the distinct ones).

The product of its digits is 240045120, while the sum is 72.

The spelling of 21139677751968 in words is "twenty-one trillion, one hundred thirty-nine billion, six hundred seventy-seven million, seven hundred fifty-one thousand, nine hundred sixty-eight".