21430805 has 8 divisors (see below), whose sum is σ = 28054944. Its totient is φ = 15586000.

The previous prime is 21430793. The next prime is 21430831. The reversal of 21430805 is 50803412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21430805 - 2¹² = 21426709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194771 + ... + 194880.

It is an arithmetic number, because the mean of its divisors is an integer number (3506868).

Almost surely, 2^21430805 is an apocalyptic number.

It is an amenable number.

21430805 is a deficient number, since it is larger than the sum of its proper divisors (6624139).

21430805 is a wasteful number, since it uses less digits than its factorization.

21430805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389667.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21430805 is about 4629.3417458641. The cubic root of 21430805 is about 277.7662623078.

The spelling of 21430805 in words is "twenty-one million, four hundred thirty thousand, eight hundred five".