621952139 has 2 divisors, whose sum is σ = 621952140. Its totient is φ = 621952138.

The previous prime is 621952073. The next prime is 621952153. The reversal of 621952139 is 931259126.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621952139 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (621952439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310976069 + 310976070.

It is an arithmetic number, because the mean of its divisors is an integer number (310976070).

Almost surely, 2^621952139 is an apocalyptic number.

621952139 is a deficient number, since it is larger than the sum of its proper divisors (1).

621952139 is an equidigital number, since it uses as much as digits as its factorization.

621952139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160, while the sum is 38.

The square root of 621952139 is about 24938.9682825894. The cubic root of 621952139 is about 853.5959029674.

The spelling of 621952139 in words is "six hundred twenty-one million, nine hundred fifty-two thousand, one hundred thirty-nine".