21672584 has 8 divisors (see below), whose sum is σ = 40636110. Its totient is φ = 10836288.

The previous prime is 21672583. The next prime is 21672589. The reversal of 21672584 is 48527612.

It can be written as a sum of positive squares in only one way, i.e., 18679684 + 2992900 = 4322^2 + 1730^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21672583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1354529 + ... + 1354544.

Almost surely, 2^21672584 is an apocalyptic number.

It is an amenable number.

21672584 is a deficient number, since it is larger than the sum of its proper divisors (18963526).

21672584 is a wasteful number, since it uses less digits than its factorization.

21672584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2709079 (or 2709075 counting only the distinct ones).

The product of its digits is 26880, while the sum is 35.

The square root of 21672584 is about 4655.3822614260. The cubic root of 21672584 is about 278.8069303978.

The spelling of 21672584 in words is "twenty-one million, six hundred seventy-two thousand, five hundred eighty-four".