20715899 has 2 divisors, whose sum is σ = 20715900. Its totient is φ = 20715898.

The previous prime is 20715853. The next prime is 20715901. The reversal of 20715899 is 99851702.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20715899 is a prime.

Together with 20715901, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20715829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10357949 + 10357950.

It is an arithmetic number, because the mean of its divisors is an integer number (10357950).

Almost surely, 2^20715899 is an apocalyptic number.

20715899 is a deficient number, since it is larger than the sum of its proper divisors (1).

20715899 is an equidigital number, since it uses as much as digits as its factorization.

20715899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 20715899 is about 4551.4721794162. The cubic root of 20715899 is about 274.6426167464.

The spelling of 20715899 in words is "twenty million, seven hundred fifteen thousand, eight hundred ninety-nine".