618916521 has 8 divisors (see below), whose sum is σ = 853678080. Its totient is φ = 398382992.

The previous prime is 618916513. The next prime is 618916523. The reversal of 618916521 is 125619816.

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

It is a cyclic number.

It is not a de Polignac number, because 618916521 - 2³ = 618916513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 618916521.

It is not an unprimeable number, because it can be changed into a prime (618916523) 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, 3556905 + ... + 3557078.

It is an arithmetic number, because the mean of its divisors is an integer number (106709760).

Almost surely, 2^618916521 is an apocalyptic number.

It is an amenable number.

618916521 is a deficient number, since it is larger than the sum of its proper divisors (234761559).

618916521 is a wasteful number, since it uses less digits than its factorization.

618916521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7114015.

The product of its digits is 25920, while the sum is 39.

The square root of 618916521 is about 24878.0329005330. The cubic root of 618916521 is about 852.2048965538.

The spelling of 618916521 in words is "six hundred eighteen million, nine hundred sixteen thousand, five hundred twenty-one".