617838989 has 4 divisors (see below), whose sum is σ = 618564156. Its totient is φ = 617113824.

The previous prime is 617838983. The next prime is 617839009. The reversal of 617838989 is 989838716.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26522500 + 591316489 = 5150^2 + 24317^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-617838989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (617838983) 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, 361304 + ... + 363009.

It is an arithmetic number, because the mean of its divisors is an integer number (154641039).

Almost surely, 2^617838989 is an apocalyptic number.

It is an amenable number.

617838989 is a deficient number, since it is larger than the sum of its proper divisors (725167).

617838989 is an equidigital number, since it uses as much as digits as its factorization.

617838989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725166.

The product of its digits is 5225472, while the sum is 59.

The square root of 617838989 is about 24856.3671722157. The cubic root of 617838989 is about 851.7100471204.

The spelling of 617838989 in words is "six hundred seventeen million, eight hundred thirty-eight thousand, nine hundred eighty-nine".