615997 has 2 divisors, whose sum is σ = 615998. Its totient is φ = 615996.

The previous prime is 615971. The next prime is 616003. The reversal of 615997 is 799516.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 586756 + 29241 = 766^2 + 171^2 .

It is a cyclic number.

It is not a de Polignac number, because 615997 - 2⁷ = 615869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (615907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 307998 + 307999.

It is an arithmetic number, because the mean of its divisors is an integer number (307999).

2⁶¹⁵⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

615997 is a deficient number, since it is larger than the sum of its proper divisors (1).

615997 is an equidigital number, since it uses as much as digits as its factorization.

615997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17010, while the sum is 37.

The square root of 615997 is about 784.8547636346. The cubic root of 615997 is about 85.0862791748.

The spelling of 615997 in words is "six hundred fifteen thousand, nine hundred ninety-seven".