616591901 has 2 divisors, whose sum is σ = 616591902. Its totient is φ = 616591900.

The previous prime is 616591883. The next prime is 616591957. The reversal of 616591901 is 109195616.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 616528900 + 63001 = 24830^2 + 251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-616591901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (616591201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308295950 + 308295951.

It is an arithmetic number, because the mean of its divisors is an integer number (308295951).

Almost surely, 2^616591901 is an apocalyptic number.

It is an amenable number.

616591901 is a deficient number, since it is larger than the sum of its proper divisors (1).

616591901 is an equidigital number, since it uses as much as digits as its factorization.

616591901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 38.

The square root of 616591901 is about 24831.2686143902. The cubic root of 616591901 is about 851.1366114065.

The spelling of 616591901 in words is "six hundred sixteen million, five hundred ninety-one thousand, nine hundred one".