21210212120120 has 64 divisors (see below), whose sum is σ = 48637118930400. Its totient is φ = 8322194644480.

The previous prime is 21210212120113. The next prime is 21210212120159. The reversal of 21210212120120 is 2102121201212.

It is a congruent number.

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, 8659739 + ... + 10835658.

Almost surely, 2^{21210212120120} is an apocalyptic number.

21210212120120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210212120120 is an abundant number, since it is smaller than the sum of its proper divisors (27426906810280).

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

21210212120120 is a wasteful number, since it uses less digits than its factorization.

21210212120120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19495928 (or 19495924 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21210212120120 its reverse (2102121201212), we get a palindrome (23312333321332).

The spelling of 21210212120120 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, one hundred twenty thousand, one hundred twenty".