21398544806 has 8 divisors (see below), whose sum is σ = 32265869184. Its totient is φ = 10643255080.

The previous prime is 21398544763. The next prime is 21398544847. The reversal of 21398544806 is 60844589312.

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, 28008185 + ... + 28008948.

It is an arithmetic number, because the mean of its divisors is an integer number (4033233648).

Almost surely, 2^21398544806 is an apocalyptic number.

21398544806 is a deficient number, since it is larger than the sum of its proper divisors (10867324378).

21398544806 is a wasteful number, since it uses less digits than its factorization.

21398544806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56017326.

The product of its (nonzero) digits is 1658880, while the sum is 50.

The spelling of 21398544806 in words is "twenty-one billion, three hundred ninety-eight million, five hundred forty-four thousand, eight hundred six".