21998116 has 24 divisors (see below), whose sum is σ = 44202816. Its totient is φ = 9383520.

The previous prime is 21998113. The next prime is 21998129. The reversal of 21998116 is 61189912.

It is not an unprimeable number, because it can be changed into a prime (21998111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4626 + ... + 8086.

It is an arithmetic number, because the mean of its divisors is an integer number (1841784).

Almost surely, 2^21998116 is an apocalyptic number.

It is an amenable number.

21998116 is an abundant number, since it is smaller than the sum of its proper divisors (22204700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21998116 is a wasteful number, since it uses less digits than its factorization.

21998116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3699 (or 3697 counting only the distinct ones).

The product of its digits is 7776, while the sum is 37.

The square root of 21998116 is about 4690.2149204487. The cubic root of 21998116 is about 280.1959342886.

The spelling of 21998116 in words is "twenty-one million, nine hundred ninety-eight thousand, one hundred sixteen".