21672814 has 4 divisors (see below), whose sum is σ = 32509224. Its totient is φ = 10836406.

The previous prime is 21672811. The next prime is 21672823. The reversal of 21672814 is 41827612.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21672811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5418202 + ... + 5418205.

It is an arithmetic number, because the mean of its divisors is an integer number (8127306).

Almost surely, 2^21672814 is an apocalyptic number.

21672814 is a deficient number, since it is larger than the sum of its proper divisors (10836410).

21672814 is a wasteful number, since it uses less digits than its factorization.

21672814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10836409.

The product of its digits is 5376, while the sum is 31.

The square root of 21672814 is about 4655.4069639506. The cubic root of 21672814 is about 278.8079166726.

The spelling of 21672814 in words is "twenty-one million, six hundred seventy-two thousand, eight hundred fourteen".