718722021 has 4 divisors (see below), whose sum is σ = 958296032. Its totient is φ = 479148012.

The previous prime is 718722007. The next prime is 718722023. The reversal of 718722021 is 120227817.

It is a happy number.

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 not a de Polignac number, because 718722021 - 2⁵ = 718721989 is a prime.

It is a super-2 number, since 2×718722021² = 1033122686940648882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 718722021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (718722023) 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, 119787001 + ... + 119787006.

It is an arithmetic number, because the mean of its divisors is an integer number (239574008).

Almost surely, 2^718722021 is an apocalyptic number.

It is an amenable number.

718722021 is a deficient number, since it is larger than the sum of its proper divisors (239574011).

718722021 is a wasteful number, since it uses less digits than its factorization.

718722021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239574010.

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 718722021 is about 26808.9914207902. The cubic root of 718722021 is about 895.7503444036.

Adding to 718722021 its reverse (120227817), we get a palindrome (838949838).

The spelling of 718722021 in words is "seven hundred eighteen million, seven hundred twenty-two thousand, twenty-one".