21995598 has 16 divisors (see below), whose sum is σ = 45064656. Its totient is φ = 7152960.

The previous prime is 21995593. The next prime is 21995599. The reversal of 21995598 is 89559912.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21995593) 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, 44461 + ... + 44952.

It is an arithmetic number, because the mean of its divisors is an integer number (2816541).

Almost surely, 2^21995598 is an apocalyptic number.

21995598 is an abundant number, since it is smaller than the sum of its proper divisors (23069058).

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

21995598 is a wasteful number, since it uses less digits than its factorization.

21995598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89459.

The product of its digits is 291600, while the sum is 48.

The square root of 21995598 is about 4689.9464815710. The cubic root of 21995598 is about 280.1852430657.

The spelling of 21995598 in words is "twenty-one million, nine hundred ninety-five thousand, five hundred ninety-eight".