21120541 has 8 divisors (see below), whose sum is σ = 22781304. Its totient is φ = 19464960.

The previous prime is 21120523. The next prime is 21120551. The reversal of 21120541 is 14502112.

It can be written as a sum of positive squares in 4 ways, for example, as 52441 + 21068100 = 229^2 + 4590^2 .

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 21120541 - 2¹³ = 21112349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120551) 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, 13521 + ... + 15001.

It is an arithmetic number, because the mean of its divisors is an integer number (2847663).

Almost surely, 2^21120541 is an apocalyptic number.

It is an amenable number.

21120541 is a deficient number, since it is larger than the sum of its proper divisors (1660763).

21120541 is a wasteful number, since it uses less digits than its factorization.

21120541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21120541 is about 4595.7089768609. The cubic root of 21120541 is about 276.4192893690.

Adding to 21120541 its reverse (14502112), we get a palindrome (35622653).

The spelling of 21120541 in words is "twenty-one million, one hundred twenty thousand, five hundred forty-one".