21411431 has 2 divisors, whose sum is σ = 21411432. Its totient is φ = 21411430.

The previous prime is 21411407. The next prime is 21411433. The reversal of 21411431 is 13411412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21411431 - 2¹⁰ = 21410407 is a prime.

It is a super-2 number, since 2×21411431² = 916898754935522, which contains 22 as substring.

Together with 21411433, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21411433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10705715 + 10705716.

It is an arithmetic number, because the mean of its divisors is an integer number (10705716).

Almost surely, 2^21411431 is an apocalyptic number.

21411431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21411431 is an equidigital number, since it uses as much as digits as its factorization.

21411431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 17.

The square root of 21411431 is about 4627.2487506076. The cubic root of 21411431 is about 277.6825344523.

Adding to 21411431 its reverse (13411412), we get a palindrome (34822843).

The spelling of 21411431 in words is "twenty-one million, four hundred eleven thousand, four hundred thirty-one".