21319699 has 2 divisors, whose sum is σ = 21319700. Its totient is φ = 21319698.

The previous prime is 21319693. The next prime is 21319703. The reversal of 21319699 is 99691312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21319699 - 2¹¹ = 21317651 is a prime.

It is not a weakly prime, because it can be changed into another prime (21319693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10659849 + 10659850.

It is an arithmetic number, because the mean of its divisors is an integer number (10659850).

Almost surely, 2^21319699 is an apocalyptic number.

21319699 is a deficient number, since it is larger than the sum of its proper divisors (1).

21319699 is an equidigital number, since it uses as much as digits as its factorization.

21319699 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26244, while the sum is 40.

The square root of 21319699 is about 4617.3259577379. The cubic root of 21319699 is about 277.2854126565.

The spelling of 21319699 in words is "twenty-one million, three hundred nineteen thousand, six hundred ninety-nine".