21801706 has 8 divisors (see below), whose sum is σ = 32729760. Its totient is φ = 10891788.

The previous prime is 21801673. The next prime is 21801719. The reversal of 21801706 is 60710812.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 966 + ... + 6673.

It is an arithmetic number, because the mean of its divisors is an integer number (4091220).

Almost surely, 2^21801706 is an apocalyptic number.

21801706 is a deficient number, since it is larger than the sum of its proper divisors (10928054).

21801706 is a wasteful number, since it uses less digits than its factorization.

21801706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9068.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 21801706 is about 4669.2297009250. The cubic root of 21801706 is about 279.3595310131.

The spelling of 21801706 in words is "twenty-one million, eight hundred one thousand, seven hundred six".