21135672 has 48 divisors (see below), whose sum is σ = 57468840. Its totient is φ = 7017408.

The previous prime is 21135649. The next prime is 21135677. The reversal of 21135672 is 27653112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135677) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26463 + ... + 27249.

Almost surely, 2^21135672 is an apocalyptic number.

It is an amenable number.

21135672 is an abundant number, since it is smaller than the sum of its proper divisors (36333168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21135672 is a wasteful number, since it uses less digits than its factorization.

21135672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1172 (or 1165 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 21135672 is about 4597.3548916741. The cubic root of 21135672 is about 276.4852836045.

Adding to 21135672 its reverse (27653112), we get a palindrome (48788784).

The spelling of 21135672 in words is "twenty-one million, one hundred thirty-five thousand, six hundred seventy-two".