20570399 has 2 divisors, whose sum is σ = 20570400. Its totient is φ = 20570398.

The previous prime is 20570387. The next prime is 20570401. The reversal of 20570399 is 99307502.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20570399 is a prime.

Together with 20570401, 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 (20570299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10285199 + 10285200.

It is an arithmetic number, because the mean of its divisors is an integer number (10285200).

Almost surely, 2^20570399 is an apocalyptic number.

20570399 is a deficient number, since it is larger than the sum of its proper divisors (1).

20570399 is an equidigital number, since it uses as much as digits as its factorization.

20570399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17010, while the sum is 35.

The square root of 20570399 is about 4535.4601751090. The cubic root of 20570399 is about 273.9981130103.

The spelling of 20570399 in words is "twenty million, five hundred seventy thousand, three hundred ninety-nine".