21101220210 has 64 divisors (see below), whose sum is σ = 58052680704. Its totient is φ = 4808548800.

The previous prime is 21101220209. The next prime is 21101220253. The reversal of 21101220210 is 1202210112.

It is a super-2 number, since 2×21101220210² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82276 + ... + 221295.

It is an arithmetic number, because the mean of its divisors is an integer number (907073136).

Almost surely, 2^21101220210 is an apocalyptic number.

21101220210 is an abundant number, since it is smaller than the sum of its proper divisors (36951460494).

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

21101220210 is a wasteful number, since it uses less digits than its factorization.

21101220210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303919.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21101220210 its reverse (1202210112), we get a palindrome (22303430322).

The spelling of 21101220210 in words is "twenty-one billion, one hundred one million, two hundred twenty thousand, two hundred ten".