21210020202120 has 32 divisors (see below), whose sum is σ = 63630060606720. Its totient is φ = 5656005387200.

The previous prime is 21210020202071. The next prime is 21210020202169. The reversal of 21210020202120 is 2120202001212.

It is an interprime number because it is at equal distance from previous prime (21210020202071) and next prime (21210020202169).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21210020202120.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88375084056 + ... + 88375084295.

It is an arithmetic number, because the mean of its divisors is an integer number (1988439393960).

Almost surely, 2^{21210020202120} is an apocalyptic number.

21210020202120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210020202120 is an abundant number, since it is smaller than the sum of its proper divisors (42420040404600).

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

21210020202120 is a wasteful number, since it uses less digits than its factorization.

21210020202120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176750168365 (or 176750168361 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21210020202120 its reverse (2120202001212), we get a palindrome (23330222203332).

The spelling of 21210020202120 in words is "twenty-one trillion, two hundred ten billion, twenty million, two hundred two thousand, one hundred twenty".