21097146 has 48 divisors (see below), whose sum is σ = 49806144. Its totient is φ = 5939136.

The previous prime is 21097129. The next prime is 21097159. The reversal of 21097146 is 64179012.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20971 + ... + 21953.

It is an arithmetic number, because the mean of its divisors is an integer number (1037628).

Almost surely, 2^21097146 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21097146, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24903072).

21097146 is an abundant number, since it is smaller than the sum of its proper divisors (28708998).

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

21097146 is a wasteful number, since it uses less digits than its factorization.

21097146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1075 (or 1068 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 21097146 is about 4593.1629624911. The cubic root of 21097146 is about 276.3171894198.

The spelling of 21097146 in words is "twenty-one million, ninety-seven thousand, one hundred forty-six".