21399814 has 8 divisors (see below), whose sum is σ = 33789240. Its totient is φ = 10136736.

The previous prime is 21399803. The next prime is 21399823. The reversal of 21399814 is 41899312.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281539 + ... + 281614.

It is an arithmetic number, because the mean of its divisors is an integer number (4223655).

Almost surely, 2^21399814 is an apocalyptic number.

21399814 is a deficient number, since it is larger than the sum of its proper divisors (12389426).

21399814 is a wasteful number, since it uses less digits than its factorization.

21399814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 563174.

The product of its digits is 15552, while the sum is 37.

The square root of 21399814 is about 4625.9932987414. The cubic root of 21399814 is about 277.6323054946.

The spelling of 21399814 in words is "twenty-one million, three hundred ninety-nine thousand, eight hundred fourteen".