21102220210 has 16 divisors (see below), whose sum is σ = 37991517336. Its totient is φ = 8439216768.

The previous prime is 21102220187. The next prime is 21102220231. The reversal of 21102220210 is 1202220112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12077790201 + 9024430009 = 109899^2 + 94997^2 .

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, 155229 + ... + 257488.

Almost surely, 2^21102220210 is an apocalyptic number.

21102220210 is a deficient number, since it is larger than the sum of its proper divisors (16889297126).

21102220210 is a wasteful number, since it uses less digits than its factorization.

21102220210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417837.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21102220210 its reverse (1202220112), we get a palindrome (22304440322).

The spelling of 21102220210 in words is "twenty-one billion, one hundred two million, two hundred twenty thousand, two hundred ten".