617981 has 8 divisors (see below), whose sum is σ = 760704. Its totient is φ = 488880.

The previous prime is 617971. The next prime is 617983. The reversal of 617981 is 189716.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 617981 - 2⁶ = 617917 is a prime.

It is a super-2 number, since 2×617981² = 763801032722, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 617981.

It is not an unprimeable number, because it can be changed into a prime (617983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3305 + ... + 3486.

It is an arithmetic number, because the mean of its divisors is an integer number (95088).

2⁶¹⁷⁹⁸¹ is an apocalyptic number.

It is an amenable number.

617981 is a deficient number, since it is larger than the sum of its proper divisors (142723).

617981 is a wasteful number, since it uses less digits than its factorization.

617981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6811.

The product of its digits is 3024, while the sum is 32.

The square root of 617981 is about 786.1176756695. The cubic root of 617981 is about 85.1775297632.

The spelling of 617981 in words is "six hundred seventeen thousand, nine hundred eighty-one".