620991139 has 2 divisors, whose sum is σ = 620991140. Its totient is φ = 620991138.

The previous prime is 620991103. The next prime is 620991157. The reversal of 620991139 is 931199026.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 620991139 - 2¹¹ = 620989091 is a prime.

It is not a weakly prime, because it can be changed into another prime (620991169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310495569 + 310495570.

It is an arithmetic number, because the mean of its divisors is an integer number (310495570).

Almost surely, 2^620991139 is an apocalyptic number.

620991139 is a deficient number, since it is larger than the sum of its proper divisors (1).

620991139 is an equidigital number, since it uses as much as digits as its factorization.

620991139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 620991139 is about 24919.6937982793. The cubic root of 620991139 is about 853.1560360448.

The spelling of 620991139 in words is "six hundred twenty million, nine hundred ninety-one thousand, one hundred thirty-nine".