21390704 has 10 divisors (see below), whose sum is σ = 41444520. Its totient is φ = 10695344.

The previous prime is 21390673. The next prime is 21390727. The reversal of 21390704 is 40709312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 668444 + ... + 668475.

It is an arithmetic number, because the mean of its divisors is an integer number (4144452).

Almost surely, 2^21390704 is an apocalyptic number.

It is an amenable number.

21390704 is a deficient number, since it is larger than the sum of its proper divisors (20053816).

21390704 is a wasteful number, since it uses less digits than its factorization.

21390704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336927 (or 1336921 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21390704 is about 4625.0085405327. The cubic root of 21390704 is about 277.5929034498.

The spelling of 21390704 in words is "twenty-one million, three hundred ninety thousand, seven hundred four".