20210609 has 2 divisors, whose sum is σ = 20210610. Its totient is φ = 20210608.

The previous prime is 20210599. The next prime is 20210657. The reversal of 20210609 is 90601202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18447025 + 1763584 = 4295^2 + 1328^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20210609 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20210669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105304 + 10105305.

It is an arithmetic number, because the mean of its divisors is an integer number (10105305).

Almost surely, 2^20210609 is an apocalyptic number.

It is an amenable number.

20210609 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210609 is an equidigital number, since it uses as much as digits as its factorization.

20210609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 20210609 is about 4495.6210916847. The cubic root of 20210609 is about 272.3912379134.

The spelling of 20210609 in words is "twenty million, two hundred ten thousand, six hundred nine".