21102012121000 has 64 divisors (see below), whose sum is σ = 49380687467280. Its totient is φ = 8440466540800.

The previous prime is 21102012120977. The next prime is 21102012121019. The reversal of 21102012121000 is 12121020112.

It can be written as a sum of positive squares in 8 ways, for example, as 1666593213156 + 19435418907844 = 1290966^2 + 4408562^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25322982 + ... + 26143018.

Almost surely, 2^{21102012121000} is an apocalyptic number.

21102012121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102012121000 is an abundant number, since it is smaller than the sum of its proper divisors (28278675346280).

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

21102012121000 is a wasteful number, since it uses less digits than its factorization.

21102012121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845791 (or 845777 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21102012121000 its reverse (12121020112), we get a palindrome (21114133141112).

The spelling of 21102012121000 in words is "twenty-one trillion, one hundred two billion, twelve million, one hundred twenty-one thousand".