21442479 has 16 divisors (see below), whose sum is σ = 29317248. Its totient is φ = 13936032.

The previous prime is 21442471. The next prime is 21442489. The reversal of 21442479 is 97424412.

It is not a de Polignac number, because 21442479 - 2³ = 21442471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442471) 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, 21009 + ... + 22005.

It is an arithmetic number, because the mean of its divisors is an integer number (1832328).

Almost surely, 2^21442479 is an apocalyptic number.

21442479 is a deficient number, since it is larger than the sum of its proper divisors (7874769).

21442479 is a wasteful number, since it uses less digits than its factorization.

21442479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1174.

The product of its digits is 16128, while the sum is 33.

The square root of 21442479 is about 4630.6024446070. The cubic root of 21442479 is about 277.8166890142.

The spelling of 21442479 in words is "twenty-one million, four hundred forty-two thousand, four hundred seventy-nine".