642615431 has 2 divisors, whose sum is σ = 642615432. Its totient is φ = 642615430.

The previous prime is 642615409. The next prime is 642615497. The reversal of 642615431 is 134516246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642615431 - 2¹⁸ = 642353287 is a prime.

It is a super-2 number, since 2×642615431² = 825909184318631522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642612431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321307715 + 321307716.

It is an arithmetic number, because the mean of its divisors is an integer number (321307716).

Almost surely, 2^642615431 is an apocalyptic number.

642615431 is a deficient number, since it is larger than the sum of its proper divisors (1).

642615431 is an equidigital number, since it uses as much as digits as its factorization.

642615431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

The square root of 642615431 is about 25349.8605716087. The cubic root of 642615431 is about 862.9461920426.

The spelling of 642615431 in words is "six hundred forty-two million, six hundred fifteen thousand, four hundred thirty-one".