21210221210 has 16 divisors (see below), whose sum is σ = 38716123392. Its totient is φ = 8364594000.

The previous prime is 21210221203. The next prime is 21210221239. The reversal of 21210221210 is 1212201212.

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, 14936066 + ... + 14937485.

It is an arithmetic number, because the mean of its divisors is an integer number (2419757712).

Almost surely, 2^21210221210 is an apocalyptic number.

21210221210 is a deficient number, since it is larger than the sum of its proper divisors (17505902182).

21210221210 is a wasteful number, since it uses less digits than its factorization.

21210221210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29873629.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21210221210 its reverse (1212201212), we get a palindrome (22422422422).

The spelling of 21210221210 in words is "twenty-one billion, two hundred ten million, two hundred twenty-one thousand, two hundred ten".