620688139 has 4 divisors (see below), whose sum is σ = 657199224. Its totient is φ = 584177056.

The previous prime is 620688137. The next prime is 620688149. The reversal of 620688139 is 931886026.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 620688139 - 2¹ = 620688137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 620688095 and 620688104.

It is not an unprimeable number, because it can be changed into a prime (620688137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18255517 + ... + 18255550.

It is an arithmetic number, because the mean of its divisors is an integer number (164299806).

Almost surely, 2^620688139 is an apocalyptic number.

620688139 is a deficient number, since it is larger than the sum of its proper divisors (36511085).

620688139 is a wasteful number, since it uses less digits than its factorization.

620688139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36511084.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 620688139 is about 24913.6135275475. The cubic root of 620688139 is about 853.0172534233.

It can be divided in two parts, 62068 and 8139, that added together give a palindrome (70207).

The spelling of 620688139 in words is "six hundred twenty million, six hundred eighty-eight thousand, one hundred thirty-nine".