20785819 has 2 divisors, whose sum is σ = 20785820. Its totient is φ = 20785818.

The previous prime is 20785763. The next prime is 20785871. The reversal of 20785819 is 91858702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20785819 - 2⁷ = 20785691 is a prime.

It is a super-2 number, since 2×20785819² = 864100543001522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20785019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10392909 + 10392910.

It is an arithmetic number, because the mean of its divisors is an integer number (10392910).

Almost surely, 2^20785819 is an apocalyptic number.

20785819 is a deficient number, since it is larger than the sum of its proper divisors (1).

20785819 is an equidigital number, since it uses as much as digits as its factorization.

20785819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 20785819 is about 4559.1467403452. The cubic root of 20785819 is about 274.9512596815.

The spelling of 20785819 in words is "twenty million, seven hundred eighty-five thousand, eight hundred nineteen".