21431241 has 24 divisors (see below), whose sum is σ = 33653256. Its totient is φ = 13063680.

The previous prime is 21431231. The next prime is 21431269. The reversal of 21431241 is 14213412.

It can be written as a sum of positive squares in 4 ways, for example, as 3600 + 21427641 = 60^2 + 4629^2 .

It is not a de Polignac number, because 21431241 - 2⁵ = 21431209 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21431231) 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 23 ways as a sum of consecutive naturals, for example, 12411 + ... + 14031.

It is an arithmetic number, because the mean of its divisors is an integer number (1402219).

Almost surely, 2^21431241 is an apocalyptic number.

It is an amenable number.

21431241 is a deficient number, since it is larger than the sum of its proper divisors (12222015).

21431241 is a wasteful number, since it uses less digits than its factorization.

21431241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1753 (or 1750 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21431241 is about 4629.3888365528. The cubic root of 21431241 is about 277.7681459712.

Adding to 21431241 its reverse (14213412), we get a palindrome (35644653).

The spelling of 21431241 in words is "twenty-one million, four hundred thirty-one thousand, two hundred forty-one".