21140121 has 4 divisors (see below), whose sum is σ = 28186832. Its totient is φ = 14093412.

The previous prime is 21140107. The next prime is 21140123. The reversal of 21140121 is 12104112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21140121 - 2⁵ = 21140089 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21140097 and 21140106.

It is not an unprimeable number, because it can be changed into a prime (21140123) 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, 3523351 + ... + 3523356.

It is an arithmetic number, because the mean of its divisors is an integer number (7046708).

Almost surely, 2^21140121 is an apocalyptic number.

It is an amenable number.

21140121 is a deficient number, since it is larger than the sum of its proper divisors (7046711).

21140121 is an equidigital number, since it uses as much as digits as its factorization.

21140121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7046710.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 21140121 is about 4597.8387314041. The cubic root of 21140121 is about 276.5046820371.

Adding to 21140121 its reverse (12104112), we get a palindrome (33244233).

The spelling of 21140121 in words is "twenty-one million, one hundred forty thousand, one hundred twenty-one".