21098242 has 16 divisors (see below), whose sum is σ = 34712064. Its totient is φ = 9538000.

The previous prime is 21098221. The next prime is 21098257. The reversal of 21098242 is 24289012.

It is a self number, because there is not a number n which added to its sum of digits gives 21098242.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1692 + ... + 6712.

It is an arithmetic number, because the mean of its divisors is an integer number (2169504).

Almost surely, 2^21098242 is an apocalyptic number.

21098242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21098242 is a deficient number, since it is larger than the sum of its proper divisors (13613822).

21098242 is a wasteful number, since it uses less digits than its factorization.

21098242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5225.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21098242 is about 4593.2822687050. The cubic root of 21098242 is about 276.3219742439.

The spelling of 21098242 in words is "twenty-one million, ninety-eight thousand, two hundred forty-two".