21465799 has 2 divisors, whose sum is σ = 21465800. Its totient is φ = 21465798.

The previous prime is 21465779. The next prime is 21465803. The reversal of 21465799 is 99756412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21465799 - 2¹⁹ = 20941511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21465749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732899 + 10732900.

It is an arithmetic number, because the mean of its divisors is an integer number (10732900).

Almost surely, 2^21465799 is an apocalyptic number.

21465799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21465799 is an equidigital number, since it uses as much as digits as its factorization.

21465799 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 43.

The square root of 21465799 is about 4633.1197912422. The cubic root of 21465799 is about 277.9173667072.

The spelling of 21465799 in words is "twenty-one million, four hundred sixty-five thousand, seven hundred ninety-nine".