21120660620064 has 168 divisors, whose sum is σ = 63864005874732. Its totient is φ = 6868507207680.

The previous prime is 21120660620047. The next prime is 21120660620107. The reversal of 21120660620064 is 46002606602112.

21120660620064 is a `hidden beast` number, since 2 + 1 + 1 + 20 + 6 + 6 + 0 + 620 + 0 + 6 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15328070651664 + 5792589968400 = 3915108^2 + 2406780^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 27 ways as a sum of consecutive naturals, for example, 10084749 + ... + 11997644.

Almost surely, 2^{21120660620064} is an apocalyptic number.

21120660620064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21120660620064 is an abundant number, since it is smaller than the sum of its proper divisors (42743345254668).

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

21120660620064 is an equidigital number, since it uses as much as digits as its factorization.

21120660620064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22082462 (or 22082439 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The spelling of 21120660620064 in words is "twenty-one trillion, one hundred twenty billion, six hundred sixty million, six hundred twenty thousand, sixty-four".