21198798 has 12 divisors (see below), whose sum is σ = 45930768. Its totient is φ = 7066260.

The previous prime is 21198787. The next prime is 21198799. The reversal of 21198798 is 89789112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21198799) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 588838 + ... + 588873.

It is an arithmetic number, because the mean of its divisors is an integer number (3827564).

Almost surely, 2^21198798 is an apocalyptic number.

21198798 is an abundant number, since it is smaller than the sum of its proper divisors (24731970).

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

21198798 is a wasteful number, since it uses less digits than its factorization.

21198798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177719 (or 1177716 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 21198798 is about 4604.2152425793. The cubic root of 21198798 is about 276.7602699361.

The spelling of 21198798 in words is "twenty-one million, one hundred ninety-eight thousand, seven hundred ninety-eight".