21485413 has 2 divisors, whose sum is σ = 21485414. Its totient is φ = 21485412.

The previous prime is 21485357. The next prime is 21485437. The reversal of 21485413 is 31458412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11512449 + 9972964 = 3393^2 + 3158^2 .

It is a cyclic number.

It is not a de Polignac number, because 21485413 - 2¹³ = 21477221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21485213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10742706 + 10742707.

It is an arithmetic number, because the mean of its divisors is an integer number (10742707).

Almost surely, 2^21485413 is an apocalyptic number.

It is an amenable number.

21485413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21485413 is an equidigital number, since it uses as much as digits as its factorization.

21485413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 28.

The square root of 21485413 is about 4635.2360241955. The cubic root of 21485413 is about 278.0019883232.

The spelling of 21485413 in words is "twenty-one million, four hundred eighty-five thousand, four hundred thirteen".