642087631 has 2 divisors, whose sum is σ = 642087632. Its totient is φ = 642087630.

The previous prime is 642087581. The next prime is 642087659. The reversal of 642087631 is 136780246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642087631 - 2⁹ = 642087119 is a prime.

It is a super-2 number, since 2×642087631² = 824553051766384322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642087661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321043815 + 321043816.

It is an arithmetic number, because the mean of its divisors is an integer number (321043816).

Almost surely, 2^642087631 is an apocalyptic number.

642087631 is a deficient number, since it is larger than the sum of its proper divisors (1).

642087631 is an equidigital number, since it uses as much as digits as its factorization.

642087631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 642087631 is about 25339.4481194836. The cubic root of 642087631 is about 862.7098725010.

The spelling of 642087631 in words is "six hundred forty-two million, eighty-seven thousand, six hundred thirty-one".