20644708619 has 2 divisors, whose sum is σ = 20644708620. Its totient is φ = 20644708618.

The previous prime is 20644708603. The next prime is 20644708649. The reversal of 20644708619 is 91680744602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20644708619 - 2⁴ = 20644708603 is a prime.

It is a super-2 number, since 2×20644708619² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20644708649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322354309 + 10322354310.

It is an arithmetic number, because the mean of its divisors is an integer number (10322354310).

Almost surely, 2^20644708619 is an apocalyptic number.

20644708619 is a deficient number, since it is larger than the sum of its proper divisors (1).

20644708619 is an equidigital number, since it uses as much as digits as its factorization.

20644708619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 47.

The spelling of 20644708619 in words is "twenty billion, six hundred forty-four million, seven hundred eight thousand, six hundred nineteen".