721875806 has 4 divisors (see below), whose sum is σ = 1082813712. Its totient is φ = 360937902.

The previous prime is 721875799. The next prime is 721875841. The reversal of 721875806 is 608578127.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×721875806² = 1042209358576299272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180468950 + ... + 180468953.

It is an arithmetic number, because the mean of its divisors is an integer number (270703428).

Almost surely, 2^721875806 is an apocalyptic number.

721875806 is a deficient number, since it is larger than the sum of its proper divisors (360937906).

721875806 is a wasteful number, since it uses less digits than its factorization.

721875806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360937905.

The product of its (nonzero) digits is 188160, while the sum is 44.

The square root of 721875806 is about 26867.7465746571. The cubic root of 721875806 is about 897.0586304443.

The spelling of 721875806 in words is "seven hundred twenty-one million, eight hundred seventy-five thousand, eight hundred six".