1617998957 has 4 divisors (see below), whose sum is σ = 1618208796. Its totient is φ = 1617789120.

The previous prime is 1617998933. The next prime is 1617998981. The reversal of 1617998957 is 7598997161.

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

It is an interprime number because it is at equal distance from previous prime (1617998933) and next prime (1617998981).

It can be written as a sum of positive squares in 2 ways, for example, as 704690116 + 913308841 = 26546^2 + 30221^2 .

It is a cyclic number.

It is not a de Polignac number, because 1617998957 - 2²⁰ = 1616950381 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1617998957.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1617998927) 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, 92894 + ... + 108927.

It is an arithmetic number, because the mean of its divisors is an integer number (404552199).

Almost surely, 2^1617998957 is an apocalyptic number.

It is an amenable number.

1617998957 is a deficient number, since it is larger than the sum of its proper divisors (209839).

1617998957 is an equidigital number, since it uses as much as digits as its factorization.

1617998957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209838.

The product of its digits is 8573040, while the sum is 62.

The square root of 1617998957 is about 40224.3577574584. The cubic root of 1617998957 is about 1173.9765240680.

The spelling of 1617998957 in words is "one billion, six hundred seventeen million, nine hundred ninety-eight thousand, nine hundred fifty-seven".