21490232 has 16 divisors (see below), whose sum is σ = 41277600. Its totient is φ = 10482880.

The previous prime is 21490213. The next prime is 21490241. The reversal of 21490232 is 23209412.

It is a junction number, because it is equal to n+sod(n) for n = 21490198 and 21490207.

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 3 ways as a sum of consecutive naturals, for example, 32432 + ... + 33087.

It is an arithmetic number, because the mean of its divisors is an integer number (2579850).

Almost surely, 2^21490232 is an apocalyptic number.

It is an amenable number.

21490232 is a deficient number, since it is larger than the sum of its proper divisors (19787368).

21490232 is a wasteful number, since it uses less digits than its factorization.

21490232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65566 (or 65562 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21490232 is about 4635.7558175555. The cubic root of 21490232 is about 278.0227712831.

Adding to 21490232 its reverse (23209412), we get a palindrome (44699644).

The spelling of 21490232 in words is "twenty-one million, four hundred ninety thousand, two hundred thirty-two".