618746721 has 8 divisors (see below), whose sum is σ = 826403424. Its totient is φ = 411793920.

The previous prime is 618746719. The next prime is 618746731. The reversal of 618746721 is 127647816.

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

It is not a de Polignac number, because 618746721 - 2¹ = 618746719 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (618746731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 173920 + ... + 177441.

It is an arithmetic number, because the mean of its divisors is an integer number (103300428).

Almost surely, 2^618746721 is an apocalyptic number.

It is an amenable number.

618746721 is a deficient number, since it is larger than the sum of its proper divisors (207656703).

618746721 is a wasteful number, since it uses less digits than its factorization.

618746721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351951.

The product of its digits is 112896, while the sum is 42.

The square root of 618746721 is about 24874.6200171983. The cubic root of 618746721 is about 852.1269551719.

The spelling of 618746721 in words is "six hundred eighteen million, seven hundred forty-six thousand, seven hundred twenty-one".