21299417 has 2 divisors, whose sum is σ = 21299418. Its totient is φ = 21299416.

The previous prime is 21299407. The next prime is 21299423. The reversal of 21299417 is 71499212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14969161 + 6330256 = 3869^2 + 2516^2 .

It is a cyclic number.

It is not a de Polignac number, because 21299417 - 2¹² = 21295321 is a prime.

It is not a weakly prime, because it can be changed into another prime (21299407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10649708 + 10649709.

It is an arithmetic number, because the mean of its divisors is an integer number (10649709).

Almost surely, 2^21299417 is an apocalyptic number.

It is an amenable number.

21299417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21299417 is an equidigital number, since it uses as much as digits as its factorization.

21299417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 21299417 is about 4615.1291422884. The cubic root of 21299417 is about 277.1974550815.

The spelling of 21299417 in words is "twenty-one million, two hundred ninety-nine thousand, four hundred seventeen".