642673139 has 2 divisors, whose sum is σ = 642673140. Its totient is φ = 642673138.

The previous prime is 642673123. The next prime is 642673243. The reversal of 642673139 is 931376246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642673139 - 2⁴ = 642673123 is a prime.

It is a super-2 number, since 2×642673139² = 826057527184226642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 642673096 and 642673105.

It is not a weakly prime, because it can be changed into another prime (642673039) 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, 321336569 + 321336570.

It is an arithmetic number, because the mean of its divisors is an integer number (321336570).

Almost surely, 2^642673139 is an apocalyptic number.

642673139 is a deficient number, since it is larger than the sum of its proper divisors (1).

642673139 is an equidigital number, since it uses as much as digits as its factorization.

642673139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 41.

The square root of 642673139 is about 25350.9987771685. The cubic root of 642673139 is about 862.9720226332.

The spelling of 642673139 in words is "six hundred forty-two million, six hundred seventy-three thousand, one hundred thirty-nine".