2918445721 has 4 divisors (see below), whose sum is σ = 2918608000. Its totient is φ = 2918283444.

The previous prime is 2918445701. The next prime is 2918445731. The reversal of 2918445721 is 1275448192.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2918445721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2918445701) 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, 50241 + ... + 91438.

It is an arithmetic number, because the mean of its divisors is an integer number (729652000).

Almost surely, 2^2918445721 is an apocalyptic number.

It is an amenable number.

2918445721 is a deficient number, since it is larger than the sum of its proper divisors (162279).

2918445721 is a wasteful number, since it uses less digits than its factorization.

2918445721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162278.

The product of its digits is 161280, while the sum is 43.

The square root of 2918445721 is about 54022.6408184568. The cubic root of 2918445721 is about 1429.0602528608.

The spelling of 2918445721 in words is "two billion, nine hundred eighteen million, four hundred forty-five thousand, seven hundred twenty-one".