617218891 has 4 divisors (see below), whose sum is σ = 619914400. Its totient is φ = 614523384.

The previous prime is 617218871. The next prime is 617218913. The reversal of 617218891 is 198812716.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 617218891 - 2⁵ = 617218859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (617218841) 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, 1347411 + ... + 1347868.

It is an arithmetic number, because the mean of its divisors is an integer number (154978600).

Almost surely, 2^617218891 is an apocalyptic number.

617218891 is a deficient number, since it is larger than the sum of its proper divisors (2695509).

617218891 is a wasteful number, since it uses less digits than its factorization.

617218891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2695508.

The product of its digits is 48384, while the sum is 43.

The square root of 617218891 is about 24843.8904159554. The cubic root of 617218891 is about 851.4250103517.

The spelling of 617218891 in words is "six hundred seventeen million, two hundred eighteen thousand, eight hundred ninety-one".