20785579 has 2 divisors, whose sum is σ = 20785580. Its totient is φ = 20785578.

The previous prime is 20785573. The next prime is 20785613. The reversal of 20785579 is 97558702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20785579 - 2¹¹ = 20783531 is a prime.

It is not a weakly prime, because it can be changed into another prime (20785573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10392789 + 10392790.

It is an arithmetic number, because the mean of its divisors is an integer number (10392790).

Almost surely, 2^20785579 is an apocalyptic number.

20785579 is a deficient number, since it is larger than the sum of its proper divisors (1).

20785579 is an equidigital number, since it uses as much as digits as its factorization.

20785579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 176400, while the sum is 43.

The square root of 20785579 is about 4559.1204195546. The cubic root of 20785579 is about 274.9502014511.

The spelling of 20785579 in words is "twenty million, seven hundred eighty-five thousand, five hundred seventy-nine".