21998596 has 12 divisors (see below), whose sum is σ = 38694348. Its totient is φ = 10943072.

The previous prime is 21998593. The next prime is 21998597. The reversal of 21998596 is 69589912.

It can be written as a sum of positive squares in 2 ways, for example, as 21252100 + 746496 = 4610^2 + 864^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21998593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13171 + ... + 14746.

It is an arithmetic number, because the mean of its divisors is an integer number (3224529).

Almost surely, 2^21998596 is an apocalyptic number.

It is an amenable number.

21998596 is a deficient number, since it is larger than the sum of its proper divisors (16695752).

21998596 is a wasteful number, since it uses less digits than its factorization.

21998596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28118 (or 28116 counting only the distinct ones).

The product of its digits is 349920, while the sum is 49.

The square root of 21998596 is about 4690.2660905326. The cubic root of 21998596 is about 280.1979722369.

The spelling of 21998596 in words is "twenty-one million, nine hundred ninety-eight thousand, five hundred ninety-six".