21722211210 has 64 divisors (see below), whose sum is σ = 63085692672. Its totient is φ = 4673012736.

The previous prime is 21722211197. The next prime is 21722211211. The reversal of 21722211210 is 1211222712.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21722211211) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3038757 + ... + 3045896.

It is an arithmetic number, because the mean of its divisors is an integer number (985713948).

Almost surely, 2^21722211210 is an apocalyptic number.

21722211210 is an abundant number, since it is smaller than the sum of its proper divisors (41363481462).

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

21722211210 is a wasteful number, since it uses less digits than its factorization.

21722211210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6084687.

The product of its (nonzero) digits is 224, while the sum is 21.

Adding to 21722211210 its reverse (1211222712), we get a palindrome (22933433922).

The spelling of 21722211210 in words is "twenty-one billion, seven hundred twenty-two million, two hundred eleven thousand, two hundred ten".