21672542 has 8 divisors (see below), whose sum is σ = 32535000. Its totient is φ = 10827544.

The previous prime is 21672527. The next prime is 21672571. The reversal of 21672542 is 24527612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 617 + ... + 6612.

It is an arithmetic number, because the mean of its divisors is an integer number (4066875).

Almost surely, 2^21672542 is an apocalyptic number.

21672542 is a deficient number, since it is larger than the sum of its proper divisors (10862458).

21672542 is a wasteful number, since it uses less digits than its factorization.

21672542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8730.

The product of its digits is 6720, while the sum is 29.

The square root of 21672542 is about 4655.3777505161. The cubic root of 21672542 is about 278.8067502947.

The spelling of 21672542 in words is "twenty-one million, six hundred seventy-two thousand, five hundred forty-two".