9972218731 has 4 divisors (see below), whose sum is σ = 9972963000. Its totient is φ = 9971474464.

The previous prime is 9972218687. The next prime is 9972218827. The reversal of 9972218731 is 1378122799.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9972218731 - 2¹⁵ = 9972185963 is a prime.

It is a super-2 number, since 2×9972218731² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9972218831) 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, 351661 + ... + 378958.

It is an arithmetic number, because the mean of its divisors is an integer number (2493240750).

Almost surely, 2^9972218731 is an apocalyptic number.

9972218731 is a deficient number, since it is larger than the sum of its proper divisors (744269).

9972218731 is a wasteful number, since it uses less digits than its factorization.

9972218731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744268.

The product of its digits is 381024, while the sum is 49.

The square root of 9972218731 is about 99860.9970458937. The cubic root of 9972218731 is about 2152.4377419747.

The spelling of 9972218731 in words is "nine billion, nine hundred seventy-two million, two hundred eighteen thousand, seven hundred thirty-one".