20815079 has 2 divisors, whose sum is σ = 20815080. Its totient is φ = 20815078.

The previous prime is 20815073. The next prime is 20815087. The reversal of 20815079 is 97051802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20815079 - 2¹⁶ = 20749543 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20815073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10407539 + 10407540.

It is an arithmetic number, because the mean of its divisors is an integer number (10407540).

Almost surely, 2^20815079 is an apocalyptic number.

20815079 is a deficient number, since it is larger than the sum of its proper divisors (1).

20815079 is an equidigital number, since it uses as much as digits as its factorization.

20815079 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 32.

The square root of 20815079 is about 4562.3545456266. The cubic root of 20815079 is about 275.0802146165.

The spelling of 20815079 in words is "twenty million, eight hundred fifteen thousand, seventy-nine".