21002220212 has 12 divisors (see below), whose sum is σ = 37356408516. Its totient is φ = 10328960640.

The previous prime is 21002220179. The next prime is 21002220229. The reversal of 21002220212 is 21202220012.

It can be written as a sum of positive squares in 2 ways, for example, as 405377956 + 20596842256 = 20134^2 + 143516^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43037093 + ... + 43037580.

It is an arithmetic number, because the mean of its divisors is an integer number (3113034043).

Almost surely, 2^21002220212 is an apocalyptic number.

It is an amenable number.

21002220212 is a deficient number, since it is larger than the sum of its proper divisors (16354188304).

21002220212 is a wasteful number, since it uses less digits than its factorization.

21002220212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86074738 (or 86074736 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21002220212 its reverse (21202220012), we get a palindrome (42204440224).

The spelling of 21002220212 in words is "twenty-one billion, two million, two hundred twenty thousand, two hundred twelve".