642830387 has 2 divisors, whose sum is σ = 642830388. Its totient is φ = 642830386.

The previous prime is 642830351. The next prime is 642830389. The reversal of 642830387 is 783038246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642830387 - 2⁸ = 642830131 is a prime.

Together with 642830389, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (642830389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321415193 + 321415194.

It is an arithmetic number, because the mean of its divisors is an integer number (321415194).

Almost surely, 2^642830387 is an apocalyptic number.

642830387 is a deficient number, since it is larger than the sum of its proper divisors (1).

642830387 is an equidigital number, since it uses as much as digits as its factorization.

642830387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 41.

The square root of 642830387 is about 25354.1000037469. The cubic root of 642830387 is about 863.0424003261.

The spelling of 642830387 in words is "six hundred forty-two million, eight hundred thirty thousand, three hundred eighty-seven".