21411432257 has 2 divisors, whose sum is σ = 21411432258. Its totient is φ = 21411432256.

The previous prime is 21411432179. The next prime is 21411432271. The reversal of 21411432257 is 75223411412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12356767921 + 9054664336 = 111161^2 + 95156^2 .

It is a cyclic number.

It is not a de Polignac number, because 21411432257 - 2¹⁶ = 21411366721 is a prime.

It is a super-2 number, since 2×21411432257² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21411435257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10705716128 + 10705716129.

It is an arithmetic number, because the mean of its divisors is an integer number (10705716129).

Almost surely, 2^21411432257 is an apocalyptic number.

It is an amenable number.

21411432257 is a deficient number, since it is larger than the sum of its proper divisors (1).

21411432257 is an equidigital number, since it uses as much as digits as its factorization.

21411432257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 32.

Adding to 21411432257 its reverse (75223411412), we get a palindrome (96634843669).

The spelling of 21411432257 in words is "twenty-one billion, four hundred eleven million, four hundred thirty-two thousand, two hundred fifty-seven".