642374531 has 2 divisors, whose sum is σ = 642374532. Its totient is φ = 642374530.

The previous prime is 642374503. The next prime is 642374533. The reversal of 642374531 is 135473246.

642374531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642374531 is a prime.

It is a super-2 number, since 2×642374531² = 825290076154939922, which contains 22 as substring.

Together with 642374533, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 642374491 and 642374500.

It is not a weakly prime, because it can be changed into another prime (642374533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321187265 + 321187266.

It is an arithmetic number, because the mean of its divisors is an integer number (321187266).

Almost surely, 2^642374531 is an apocalyptic number.

642374531 is a deficient number, since it is larger than the sum of its proper divisors (1).

642374531 is an equidigital number, since it uses as much as digits as its factorization.

642374531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 35.

The square root of 642374531 is about 25345.1086207970. The cubic root of 642374531 is about 862.8383464532.

The spelling of 642374531 in words is "six hundred forty-two million, three hundred seventy-four thousand, five hundred thirty-one".