21440140231 has 4 divisors (see below), whose sum is σ = 21760142392. Its totient is φ = 21120138072.

The previous prime is 21440140219. The next prime is 21440140243. The reversal of 21440140231 is 13204104412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21440140219) and next prime (21440140243).

It is a cyclic number.

It is not a de Polignac number, because 21440140231 - 2⁵ = 21440140199 is a prime.

It is a super-2 number, since 2×21440140231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440140831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160000980 + ... + 160001113.

It is an arithmetic number, because the mean of its divisors is an integer number (5440035598).

Almost surely, 2^21440140231 is an apocalyptic number.

21440140231 is a deficient number, since it is larger than the sum of its proper divisors (320002161).

21440140231 is an equidigital number, since it uses as much as digits as its factorization.

21440140231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320002160.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21440140231 its reverse (13204104412), we get a palindrome (34644244643).

The spelling of 21440140231 in words is "twenty-one billion, four hundred forty million, one hundred forty thousand, two hundred thirty-one".