21121210212210 has 48 divisors (see below), whose sum is σ = 58145449294296. Its totient is φ = 5301009621504.

The previous prime is 21121210212209. The next prime is 21121210212233. The reversal of 21121210212210 is 1221201212112.

21121210212210 is a `hidden beast` number, since 2 + 11 + 21 + 210 + 212 + 210 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13579084970361 + 7542125241849 = 3684981^2 + 2746293^2 .

It is a super-2 number, since 2×21121210212210² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6902354749 + ... + 6902357808.

Almost surely, 2^{21121210212210} is an apocalyptic number.

21121210212210 is an abundant number, since it is smaller than the sum of its proper divisors (37024239082086).

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

21121210212210 is a wasteful number, since it uses less digits than its factorization.

21121210212210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13804712587 (or 13804712584 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21121210212210 its reverse (1221201212112), we get a palindrome (22342411424322).

The spelling of 21121210212210 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred ten million, two hundred twelve thousand, two hundred ten".