21098190 has 64 divisors (see below), whose sum is σ = 54976320. Its totient is φ = 5160960.

The previous prime is 21098183. The next prime is 21098191. The reversal of 21098190 is 9189012.

It is a super-2 number, since 2×21098190² = 890267242552200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21098191) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20406 + ... + 21414.

It is an arithmetic number, because the mean of its divisors is an integer number (859005).

Almost surely, 2^21098190 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21098190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27488160).

21098190 is an abundant number, since it is smaller than the sum of its proper divisors (33878130).

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

21098190 is a wasteful number, since it uses less digits than its factorization.

21098190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 21098190 is about 4593.2766082613. The cubic root of 21098190 is about 276.3217472304.

The spelling of 21098190 in words is "twenty-one million, ninety-eight thousand, one hundred ninety".