21098790 has 24 divisors (see below), whose sum is σ = 54857088. Its totient is φ = 5626320.

The previous prime is 21098783. The next prime is 21098807. The reversal of 21098790 is 9789012.

It is a happy number.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 117126 + ... + 117305.

It is an arithmetic number, because the mean of its divisors is an integer number (2285712).

Almost surely, 2^21098790 is an apocalyptic number.

21098790 is an abundant number, since it is smaller than the sum of its proper divisors (33758298).

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

21098790 is a wasteful number, since it uses less digits than its factorization.

21098790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234444 (or 234441 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 21098790 is about 4593.3419206499. The cubic root of 21098790 is about 276.3243665938.

The spelling of 21098790 in words is "twenty-one million, ninety-eight thousand, seven hundred ninety".