7218971889 has 32 divisors (see below), whose sum is σ = 10266808320. Its totient is φ = 4502289792.

The previous prime is 7218971857. The next prime is 7218971899. The reversal of 7218971889 is 9881798127.

It is not a de Polignac number, because 7218971889 - 2⁵ = 7218971857 is a prime.

It is a super-2 number, since 2×7218971889² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7218971899) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 577069 + ... + 589445.

It is an arithmetic number, because the mean of its divisors is an integer number (320837760).

Almost surely, 2^7218971889 is an apocalyptic number.

7218971889 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

It is an amenable number.

7218971889 is a deficient number, since it is larger than the sum of its proper divisors (3047836431).

7218971889 is a wasteful number, since it uses less digits than its factorization.

7218971889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12589.

The product of its digits is 4064256, while the sum is 60.

The square root of 7218971889 is about 84964.5331241219. The cubic root of 7218971889 is about 1932.6733148103.

The spelling of 7218971889 in words is "seven billion, two hundred eighteen million, nine hundred seventy-one thousand, eight hundred eighty-nine".