210564680657409 has 45 divisors (see below), whose sum is σ = 329505357057279. Its totient is φ = 129573737635680.

The previous prime is 210564680657347. The next prime is 210564680657413. The reversal of 210564680657409 is 904756086465012.

The square root of 210564680657409 is 14510847.

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

210564680657409 is a `hidden beast` number, since 2 + 1 + 0 + 56 + 4 + 6 + 8 + 0 + 6 + 574 + 0 + 9 = 666.

210564680657409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 7 ways, for example, as 125407589293809 + 85157091363600 = 11198553^2 + 9228060^2 .

It is not a de Polignac number, because 210564680657409 - 2¹¹ = 210564680655361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (210564680657459) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 7356985119 + ... + 7357013739.

Almost surely, 2^{210564680657409} is an apocalyptic number.

210564680657409 is the 14510847-th square number.

210564680657409 is the 7255424-th centered octagonal number.

It is an amenable number.

210564680657409 is a deficient number, since it is larger than the sum of its proper divisors (118940676399870).

210564680657409 is an frugal number, since it uses more digits than its factorization.

210564680657409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57300 (or 28637 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 210564680657409 in words is "two hundred ten trillion, five hundred sixty-four billion, six hundred eighty million, six hundred fifty-seven thousand, four hundred nine".