21907212210 has 160 divisors (see below), whose sum is σ = 63716693040. Its totient is φ = 5368799232.

The previous prime is 21907212203. The next prime is 21907212227. The reversal of 21907212210 is 1221270912.

It can be written as a sum of positive squares in 8 ways, for example, as 92217609 + 21814994601 = 9603^2 + 147699^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2449026 + ... + 2457954.

Almost surely, 2^21907212210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21907212210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31858346520).

21907212210 is an abundant number, since it is smaller than the sum of its proper divisors (41809480830).

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

21907212210 is a wasteful number, since it uses less digits than its factorization.

21907212210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9194 (or 9185 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The spelling of 21907212210 in words is "twenty-one billion, nine hundred seven million, two hundred twelve thousand, two hundred ten".