21597230 has 16 divisors (see below), whose sum is σ = 40565664. Its totient is φ = 8263200.

The previous prime is 21597227. The next prime is 21597241. The reversal of 21597230 is 3279512.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21597193 and 21597202.

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 7 ways as a sum of consecutive naturals, for example, 46721 + ... + 47180.

It is an arithmetic number, because the mean of its divisors is an integer number (2535354).

Almost surely, 2^21597230 is an apocalyptic number.

21597230 is a deficient number, since it is larger than the sum of its proper divisors (18968434).

21597230 is a wasteful number, since it uses less digits than its factorization.

21597230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93931.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 21597230 is about 4647.2820013423. The cubic root of 21597230 is about 278.4834246920.

The spelling of 21597230 in words is "twenty-one million, five hundred ninety-seven thousand, two hundred thirty".