21074897 has 2 divisors, whose sum is σ = 21074898. Its totient is φ = 21074896.

The previous prime is 21074843. The next prime is 21074903. The reversal of 21074897 is 79847012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18653761 + 2421136 = 4319^2 + 1556^2 .

It is a cyclic number.

It is not a de Polignac number, because 21074897 - 2¹⁰ = 21073873 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21074897.

It is not a weakly prime, because it can be changed into another prime (21074197) 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, 10537448 + 10537449.

It is an arithmetic number, because the mean of its divisors is an integer number (10537449).

Almost surely, 2^21074897 is an apocalyptic number.

It is an amenable number.

21074897 is a deficient number, since it is larger than the sum of its proper divisors (1).

21074897 is an equidigital number, since it uses as much as digits as its factorization.

21074897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 21074897 is about 4590.7403542348. The cubic root of 21074897 is about 276.2200207702.

The spelling of 21074897 in words is "twenty-one million, seventy-four thousand, eight hundred ninety-seven".