21102006190864 has 45 divisors (see below), whose sum is σ = 41412070165557. Its totient is φ = 10416729478272.

The previous prime is 21102006190849. The next prime is 21102006190873. The reversal of 21102006190864 is 46809160020112.

The square root of 21102006190864 is 4593692.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5026653680400 + 16075352510464 = 2242020^2 + 4009408^2 .

It is a Duffinian number.

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 8 ways as a sum of consecutive naturals, for example, 1451599404 + ... + 1451613940.

Almost surely, 2^{21102006190864} is an apocalyptic number.

21102006190864 is the 4593692-nd square number.

It is an amenable number.

21102006190864 is a deficient number, since it is larger than the sum of its proper divisors (20310063974693).

21102006190864 is an frugal number, since it uses more digits than its factorization.

21102006190864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29240 (or 14618 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The spelling of 21102006190864 in words is "twenty-one trillion, one hundred two billion, six million, one hundred ninety thousand, eight hundred sixty-four".