642716783 has 2 divisors, whose sum is σ = 642716784. Its totient is φ = 642716782.

The previous prime is 642716777. The next prime is 642716813. The reversal of 642716783 is 387617246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642716783 - 2²⁰ = 641668207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642716383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321358391 + 321358392.

It is an arithmetic number, because the mean of its divisors is an integer number (321358392).

Almost surely, 2^642716783 is an apocalyptic number.

642716783 is a deficient number, since it is larger than the sum of its proper divisors (1).

642716783 is an equidigital number, since it uses as much as digits as its factorization.

642716783 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 44.

The square root of 642716783 is about 25351.8595570424. The cubic root of 642716783 is about 862.9915570311.

The spelling of 642716783 in words is "six hundred forty-two million, seven hundred sixteen thousand, seven hundred eighty-three".