420642139 has 2 divisors, whose sum is σ = 420642140. Its totient is φ = 420642138.

The previous prime is 420642137. The next prime is 420642163. The reversal of 420642139 is 931246024.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 420642139 - 2¹ = 420642137 is a prime.

Together with 420642137, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 420642139.

It is not a weakly prime, because it can be changed into another prime (420642137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210321069 + 210321070.

It is an arithmetic number, because the mean of its divisors is an integer number (210321070).

Almost surely, 2^420642139 is an apocalyptic number.

420642139 is a deficient number, since it is larger than the sum of its proper divisors (1).

420642139 is an equidigital number, since it uses as much as digits as its factorization.

420642139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 420642139 is about 20509.5621357454. The cubic root of 420642139 is about 749.2687028748.

The spelling of 420642139 in words is "four hundred twenty million, six hundred forty-two thousand, one hundred thirty-nine".