21580672 has 16 divisors (see below), whose sum is σ = 42993000. Its totient is φ = 10790272.

The previous prime is 21580613. The next prime is 21580673. The reversal of 21580672 is 27608512.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21580673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84172 + ... + 84427.

Almost surely, 2^21580672 is an apocalyptic number.

It is an amenable number.

21580672 is a deficient number, since it is larger than the sum of its proper divisors (21412328).

21580672 is an equidigital number, since it uses as much as digits as its factorization.

21580672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168613 (or 168601 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 21580672 is about 4645.5001883543. The cubic root of 21580672 is about 278.4122379788.

It can be divided in two parts, 2158067 and 2, that multiplied together give a palindrome (4316134).

The spelling of 21580672 in words is "twenty-one million, five hundred eighty thousand, six hundred seventy-two".