21429799 has 2 divisors, whose sum is σ = 21429800. Its totient is φ = 21429798.

The previous prime is 21429763. The next prime is 21429817. The reversal of 21429799 is 99792412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21429799 - 2⁷ = 21429671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21429719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10714899 + 10714900.

It is an arithmetic number, because the mean of its divisors is an integer number (10714900).

Almost surely, 2^21429799 is an apocalyptic number.

21429799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21429799 is an equidigital number, since it uses as much as digits as its factorization.

21429799 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 43.

The square root of 21429799 is about 4629.2330898325. The cubic root of 21429799 is about 277.7619159595.

The spelling of 21429799 in words is "twenty-one million, four hundred twenty-nine thousand, seven hundred ninety-nine".