21666032 has 10 divisors (see below), whose sum is σ = 41977968. Its totient is φ = 10833008.

The previous prime is 21666019. The next prime is 21666037. The reversal of 21666032 is 23066612.

It is a junction number, because it is equal to n+sod(n) for n = 21665992 and 21666010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666037) by changing a digit.

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 as a sum of consecutive naturals, namely, 677048 + ... + 677079.

Almost surely, 2^21666032 is an apocalyptic number.

It is an amenable number.

21666032 is a deficient number, since it is larger than the sum of its proper divisors (20311936).

21666032 is a wasteful number, since it uses less digits than its factorization.

21666032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354135 (or 1354129 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21666032 is about 4654.6785066211. The cubic root of 21666032 is about 278.7788315007.

The spelling of 21666032 in words is "twenty-one million, six hundred sixty-six thousand, thirty-two".