21542339 has 8 divisors (see below), whose sum is σ = 26513760. Its totient is φ = 17044416.

The previous prime is 21542321. The next prime is 21542341. The reversal of 21542339 is 93324512.

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

It is a cyclic number.

It is not a de Polignac number, because 21542339 - 2⁸ = 21542083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21542639) 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, 118274 + ... + 118455.

It is an arithmetic number, because the mean of its divisors is an integer number (3314220).

Almost surely, 2^21542339 is an apocalyptic number.

21542339 is a deficient number, since it is larger than the sum of its proper divisors (4971421).

21542339 is a wasteful number, since it uses less digits than its factorization.

21542339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236749.

The product of its digits is 6480, while the sum is 29.

The square root of 21542339 is about 4641.3725340679. The cubic root of 21542339 is about 278.2472956089.

The spelling of 21542339 in words is "twenty-one million, five hundred forty-two thousand, three hundred thirty-nine".