642431759 has 2 divisors, whose sum is σ = 642431760. Its totient is φ = 642431758.

The previous prime is 642431749. The next prime is 642431773. The reversal of 642431759 is 957134246.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642431759 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 (642431719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321215879 + 321215880.

It is an arithmetic number, because the mean of its divisors is an integer number (321215880).

Almost surely, 2^642431759 is an apocalyptic number.

642431759 is a deficient number, since it is larger than the sum of its proper divisors (1).

642431759 is an equidigital number, since it uses as much as digits as its factorization.

642431759 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 41.

The square root of 642431759 is about 25346.2375708901. The cubic root of 642431759 is about 862.8639686016.

It can be divided in two parts, 6424 and 31759, that added together give a palindrome (38183).

The spelling of 642431759 in words is "six hundred forty-two million, four hundred thirty-one thousand, seven hundred fifty-nine".