21327639 has 8 divisors (see below), whose sum is σ = 30109680. Its totient is φ = 13382016.

The previous prime is 21327637. The next prime is 21327653. The reversal of 21327639 is 93672312.

It is a happy number.

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

It is not a de Polignac number, because 21327639 - 2¹ = 21327637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21327637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 209044 + ... + 209145.

It is an arithmetic number, because the mean of its divisors is an integer number (3763710).

Almost surely, 2^21327639 is an apocalyptic number.

21327639 is a deficient number, since it is larger than the sum of its proper divisors (8782041).

21327639 is a wasteful number, since it uses less digits than its factorization.

21327639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418209.

The product of its digits is 13608, while the sum is 33.

The square root of 21327639 is about 4618.1856827113. The cubic root of 21327639 is about 277.3198311055.

The spelling of 21327639 in words is "twenty-one million, three hundred twenty-seven thousand, six hundred thirty-nine".