1721138806 has 16 divisors (see below), whose sum is σ = 2786853600. Its totient is φ = 794768128.

The previous prime is 1721138779. The next prime is 1721138831. The reversal of 1721138806 is 6088311271.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 643771 + ... + 646438.

It is an arithmetic number, because the mean of its divisors is an integer number (174178350).

Almost surely, 2^1721138806 is an apocalyptic number.

1721138806 is a deficient number, since it is larger than the sum of its proper divisors (1065714794).

1721138806 is a wasteful number, since it uses less digits than its factorization.

1721138806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1290263.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 1721138806 is about 41486.6099603233. The cubic root of 1721138806 is about 1198.4096539120.

The spelling of 1721138806 in words is "one billion, seven hundred twenty-one million, one hundred thirty-eight thousand, eight hundred six".