21672735 has 16 divisors (see below), whose sum is σ = 39630336. Its totient is φ = 9907488.

The previous prime is 21672733. The next prime is 21672769. The reversal of 21672735 is 53727612.

It is not a de Polignac number, because 21672735 - 2¹ = 21672733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21672696 and 21672705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21672733) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103099 + ... + 103308.

It is an arithmetic number, because the mean of its divisors is an integer number (2476896).

Almost surely, 2^21672735 is an apocalyptic number.

21672735 is a deficient number, since it is larger than the sum of its proper divisors (17957601).

21672735 is a wasteful number, since it uses less digits than its factorization.

21672735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206422.

The product of its digits is 17640, while the sum is 33.

The square root of 21672735 is about 4655.3984791852. The cubic root of 21672735 is about 278.8075779094.

The spelling of 21672735 in words is "twenty-one million, six hundred seventy-two thousand, seven hundred thirty-five".