21346539 has 4 divisors (see below), whose sum is σ = 28462056. Its totient is φ = 14231024.

The previous prime is 21346537. The next prime is 21346547. The reversal of 21346539 is 93564312.

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

It is a cyclic number.

It is not a de Polignac number, because 21346539 - 2¹ = 21346537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21346537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3557754 + ... + 3557759.

It is an arithmetic number, because the mean of its divisors is an integer number (7115514).

Almost surely, 2^21346539 is an apocalyptic number.

21346539 is a deficient number, since it is larger than the sum of its proper divisors (7115517).

21346539 is an equidigital number, since it uses as much as digits as its factorization.

21346539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7115516.

The product of its digits is 19440, while the sum is 33.

The square root of 21346539 is about 4620.2314877071. The cubic root of 21346539 is about 277.4017247979.

The spelling of 21346539 in words is "twenty-one million, three hundred forty-six thousand, five hundred thirty-nine".