616639 has 2 divisors, whose sum is σ = 616640. Its totient is φ = 616638.

The previous prime is 616597. The next prime is 616643. The reversal of 616639 is 936616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 616639 - 2¹⁷ = 485567 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 616639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (616669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308319 + 308320.

It is an arithmetic number, because the mean of its divisors is an integer number (308320).

2⁶¹⁶⁶³⁹ is an apocalyptic number.

616639 is a deficient number, since it is larger than the sum of its proper divisors (1).

616639 is an equidigital number, since it uses as much as digits as its factorization.

616639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 31.

The square root of 616639 is about 785.2636499928. The cubic root of 616639 is about 85.1158282500.

The spelling of 616639 in words is "six hundred sixteen thousand, six hundred thirty-nine".