21514121 has 4 divisors (see below), whose sum is σ = 21525012. Its totient is φ = 21503232.

The previous prime is 21514117. The next prime is 21514123. The reversal of 21514121 is 12141512.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 18490000 + 3024121 = 4300^2 + 1739^2 .

It is a cyclic number.

It is not a de Polignac number, because 21514121 - 2² = 21514117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21514121.

It is not an unprimeable number, because it can be changed into a prime (21514123) 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, 1556 + ... + 6741.

It is an arithmetic number, because the mean of its divisors is an integer number (5381253).

Almost surely, 2^21514121 is an apocalyptic number.

It is an amenable number.

21514121 is a deficient number, since it is larger than the sum of its proper divisors (10891).

21514121 is an equidigital number, since it uses as much as digits as its factorization.

21514121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10890.

The product of its digits is 80, while the sum is 17.

The square root of 21514121 is about 4638.3317043954. The cubic root of 21514121 is about 278.1257518138.

Adding to 21514121 its reverse (12141512), we get a palindrome (33655633).

The spelling of 21514121 in words is "twenty-one million, five hundred fourteen thousand, one hundred twenty-one".