21606232 has 8 divisors (see below), whose sum is σ = 40511700. Its totient is φ = 10803112.

The previous prime is 21606217. The next prime is 21606259. The reversal of 21606232 is 23260612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21606232² = 933658522475648, which contains 22 as substring.

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 as a sum of consecutive naturals, namely, 1350382 + ... + 1350397.

Almost surely, 2^21606232 is an apocalyptic number.

It is an amenable number.

21606232 is a deficient number, since it is larger than the sum of its proper divisors (18905468).

21606232 is a wasteful number, since it uses less digits than its factorization.

21606232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2700785 (or 2700781 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 21606232 is about 4648.2504235465. The cubic root of 21606232 is about 278.5221111280.

Adding to 21606232 its reverse (23260612), we get a palindrome (44866844).

The spelling of 21606232 in words is "twenty-one million, six hundred six thousand, two hundred thirty-two".