21206539688752 has 20 divisors (see below), whose sum is σ = 44822913433416. Its totient is φ = 9639336222080.

The previous prime is 21206539688731. The next prime is 21206539688771. The reversal of 21206539688752 is 25788693560212.

It is a super-2 number, since 2×21206539688752² (a number of 27 digits) contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 60245851213 + ... + 60245851564.

Almost surely, 2^{21206539688752} is an apocalyptic number.

21206539688752 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21206539688752 is an abundant number, since it is smaller than the sum of its proper divisors (23616373744664).

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

21206539688752 is a wasteful number, since it uses less digits than its factorization.

21206539688752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120491702796 (or 120491702790 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 64.

The spelling of 21206539688752 in words is "twenty-one trillion, two hundred six billion, five hundred thirty-nine million, six hundred eighty-eight thousand, seven hundred fifty-two".