21198398 has 32 divisors (see below), whose sum is σ = 35688576. Its totient is φ = 9380448.

The previous prime is 21198377. The next prime is 21198407. The reversal of 21198398 is 89389112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74765 + ... + 75047.

It is an arithmetic number, because the mean of its divisors is an integer number (1115268).

Almost surely, 2^21198398 is an apocalyptic number.

21198398 is a deficient number, since it is larger than the sum of its proper divisors (14490178).

21198398 is a wasteful number, since it uses less digits than its factorization.

21198398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408.

The product of its digits is 31104, while the sum is 41.

The square root of 21198398 is about 4604.1718039187. The cubic root of 21198398 is about 276.7585291959.

The spelling of 21198398 in words is "twenty-one million, one hundred ninety-eight thousand, three hundred ninety-eight".