21241231 has 16 divisors (see below), whose sum is σ = 24127488. Its totient is φ = 18525600.

The previous prime is 21241229. The next prime is 21241247. The reversal of 21241231 is 13214212.

It is not a de Polignac number, because 21241231 - 2¹ = 21241229 is a prime.

It is a super-2 number, since 2×21241231² = 902379788790722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21241261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56761 + ... + 57133.

It is an arithmetic number, because the mean of its divisors is an integer number (1507968).

Almost surely, 2^21241231 is an apocalyptic number.

21241231 is a deficient number, since it is larger than the sum of its proper divisors (2886257).

21241231 is a wasteful number, since it uses less digits than its factorization.

21241231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582.

The product of its digits is 96, while the sum is 16.

The square root of 21241231 is about 4608.8209989107. The cubic root of 21241231 is about 276.9448077815.

Adding to 21241231 its reverse (13214212), we get a palindrome (34455443).

The spelling of 21241231 in words is "twenty-one million, two hundred forty-one thousand, two hundred thirty-one".