21050413 has 2 divisors, whose sum is σ = 21050414. Its totient is φ = 21050412.

The previous prime is 21050401. The next prime is 21050417. The reversal of 21050413 is 31405012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12830724 + 8219689 = 3582^2 + 2867^2 .

It is a cyclic number.

It is not a de Polignac number, because 21050413 - 2¹⁷ = 20919341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21050417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525206 + 10525207.

It is an arithmetic number, because the mean of its divisors is an integer number (10525207).

Almost surely, 2^21050413 is an apocalyptic number.

It is an amenable number.

21050413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21050413 is an equidigital number, since it uses as much as digits as its factorization.

21050413 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21050413 is about 4588.0729070057. The cubic root of 21050413 is about 276.1130120754.

Adding to 21050413 its reverse (31405012), we get a palindrome (52455425).

The spelling of 21050413 in words is "twenty-one million, fifty thousand, four hundred thirteen".