9918221090 has 32 divisors (see below), whose sum is σ = 18929199744. Its totient is φ = 3728736000.

The previous prime is 9918221081. The next prime is 9918221099. The reversal of 9918221090 is 901228199.

It is an interprime number because it is at equal distance from previous prime (9918221081) and next prime (9918221099).

It is a super-2 number, since 2×9918221090² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9918221099) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83465 + ... + 163715.

It is an arithmetic number, because the mean of its divisors is an integer number (591537492).

Almost surely, 2^9918221090 is an apocalyptic number.

9918221090 is a deficient number, since it is larger than the sum of its proper divisors (9010978654).

9918221090 is a wasteful number, since it uses less digits than its factorization.

9918221090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81002.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 9918221090 is about 99590.2660404118. The cubic root of 9918221090 is about 2148.5456968698.

The spelling of 9918221090 in words is "nine billion, nine hundred eighteen million, two hundred twenty-one thousand, ninety".