21534121 has 8 divisors (see below), whose sum is σ = 26058240. Its totient is φ = 17371968.

The previous prime is 21534089. The next prime is 21534151. The reversal of 21534121 is 12143512.

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 21534121 - 2⁵ = 21534089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21534151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90361 + ... + 90598.

It is an arithmetic number, because the mean of its divisors is an integer number (3257280).

Almost surely, 2^21534121 is an apocalyptic number.

It is an amenable number.

21534121 is a deficient number, since it is larger than the sum of its proper divisors (4524119).

21534121 is a wasteful number, since it uses less digits than its factorization.

21534121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180983.

The product of its digits is 240, while the sum is 19.

The square root of 21534121 is about 4640.4871511513. The cubic root of 21534121 is about 278.2119090598.

Adding to 21534121 its reverse (12143512), we get a palindrome (33677633).

The spelling of 21534121 in words is "twenty-one million, five hundred thirty-four thousand, one hundred twenty-one".