620728139 has 2 divisors, whose sum is σ = 620728140. Its totient is φ = 620728138.

The previous prime is 620728127. The next prime is 620728193. The reversal of 620728139 is 931827026.

Together with next prime (620728193) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-620728139 is a prime.

It is not a weakly prime, because it can be changed into another prime (620728039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310364069 + 310364070.

It is an arithmetic number, because the mean of its divisors is an integer number (310364070).

Almost surely, 2^620728139 is an apocalyptic number.

620728139 is a deficient number, since it is larger than the sum of its proper divisors (1).

620728139 is an equidigital number, since it uses as much as digits as its factorization.

620728139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 620728139 is about 24914.4162885667. The cubic root of 620728139 is about 853.0355771488.

The spelling of 620728139 in words is "six hundred twenty million, seven hundred twenty-eight thousand, one hundred thirty-nine".