21020202010 has 16 divisors (see below), whose sum is σ = 38183488200. Its totient is φ = 8330942016.

The previous prime is 21020201977. The next prime is 21020202059. The reversal of 21020202010 is 1020202012.

It can be written as a sum of positive squares in 4 ways, for example, as 13587865489 + 7432336521 = 116567^2 + 86211^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9641205 + ... + 9643384.

Almost surely, 2^21020202010 is an apocalyptic number.

21020202010 is a deficient number, since it is larger than the sum of its proper divisors (17163286190).

21020202010 is a wasteful number, since it uses less digits than its factorization.

21020202010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19284705.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21020202010 its reverse (1020202012), we get a palindrome (22040404022).

The spelling of 21020202010 in words is "twenty-one billion, twenty million, two hundred two thousand, ten".