21120539 has 4 divisors (see below), whose sum is σ = 23040600. Its totient is φ = 19200480.

The previous prime is 21120523. The next prime is 21120551. The reversal of 21120539 is 93502112.

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 21120539 - 2⁴ = 21120523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21120559) 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, 960014 + ... + 960035.

It is an arithmetic number, because the mean of its divisors is an integer number (5760150).

Almost surely, 2^21120539 is an apocalyptic number.

21120539 is a deficient number, since it is larger than the sum of its proper divisors (1920061).

21120539 is a wasteful number, since it uses less digits than its factorization.

21120539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920060.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 21120539 is about 4595.7087592666. The cubic root of 21120539 is about 276.4192806439.

The spelling of 21120539 in words is "twenty-one million, one hundred twenty thousand, five hundred thirty-nine".