21411457 has 2 divisors, whose sum is σ = 21411458. Its totient is φ = 21411456.

The previous prime is 21411437. The next prime is 21411469. The reversal of 21411457 is 75411412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18974736 + 2436721 = 4356^2 + 1561^2 .

It is a cyclic number.

It is not a de Polignac number, because 21411457 - 2⁷ = 21411329 is a prime.

It is not a weakly prime, because it can be changed into another prime (21411407) 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 as a sum of consecutive naturals, namely, 10705728 + 10705729.

It is an arithmetic number, because the mean of its divisors is an integer number (10705729).

Almost surely, 2^21411457 is an apocalyptic number.

It is an amenable number.

21411457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21411457 is an equidigital number, since it uses as much as digits as its factorization.

21411457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1120, while the sum is 25.

The square root of 21411457 is about 4627.2515600516. The cubic root of 21411457 is about 277.6826468493.

Adding to 21411457 its reverse (75411412), we get a palindrome (96822869).

The spelling of 21411457 in words is "twenty-one million, four hundred eleven thousand, four hundred fifty-seven".