21628198 has 4 divisors (see below), whose sum is σ = 32442300. Its totient is φ = 10814098.

The previous prime is 21628193. The next prime is 21628219. The reversal of 21628198 is 89182612.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21628193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5407048 + ... + 5407051.

It is an arithmetic number, because the mean of its divisors is an integer number (8110575).

Almost surely, 2^21628198 is an apocalyptic number.

21628198 is a deficient number, since it is larger than the sum of its proper divisors (10814102).

21628198 is a wasteful number, since it uses less digits than its factorization.

21628198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10814101.

The product of its digits is 13824, while the sum is 37.

The square root of 21628198 is about 4650.6126478132. The cubic root of 21628198 is about 278.6164657655.

The spelling of 21628198 in words is "twenty-one million, six hundred twenty-eight thousand, one hundred ninety-eight".