20572661 has 2 divisors, whose sum is σ = 20572662. Its totient is φ = 20572660.

The previous prime is 20572613. The next prime is 20572663. The reversal of 20572661 is 16627502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13734436 + 6838225 = 3706^2 + 2615^2 .

It is a cyclic number.

It is not a de Polignac number, because 20572661 - 2⁶ = 20572597 is a prime.

Together with 20572663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20572663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10286330 + 10286331.

It is an arithmetic number, because the mean of its divisors is an integer number (10286331).

Almost surely, 2^20572661 is an apocalyptic number.

It is an amenable number.

20572661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20572661 is an equidigital number, since it uses as much as digits as its factorization.

20572661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20572661 is about 4535.7095365554. The cubic root of 20572661 is about 274.0081559367.

The spelling of 20572661 in words is "twenty million, five hundred seventy-two thousand, six hundred sixty-one".