642368431 has 2 divisors, whose sum is σ = 642368432. Its totient is φ = 642368430.

The previous prime is 642368423. The next prime is 642368479. The reversal of 642368431 is 134863246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642368431 - 2³ = 642368423 is a prime.

It is a super-2 number, since 2×642368431² = 825274402290803522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642368231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321184215 + 321184216.

It is an arithmetic number, because the mean of its divisors is an integer number (321184216).

Almost surely, 2^642368431 is an apocalyptic number.

642368431 is a deficient number, since it is larger than the sum of its proper divisors (1).

642368431 is an equidigital number, since it uses as much as digits as its factorization.

642368431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 37.

The square root of 642368431 is about 25344.9882817097. The cubic root of 642368431 is about 862.8356152684.

The spelling of 642368431 in words is "six hundred forty-two million, three hundred sixty-eight thousand, four hundred thirty-one".