721681827 has 16 divisors (see below), whose sum is σ = 975805440. Its totient is φ = 474357312.

The previous prime is 721681819. The next prime is 721681837. The reversal of 721681827 is 728186127.

It is not a de Polignac number, because 721681827 - 2³ = 721681819 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721681837) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 208503 + ... + 211935.

It is an arithmetic number, because the mean of its divisors is an integer number (60987840).

Almost surely, 2^721681827 is an apocalyptic number.

721681827 is a deficient number, since it is larger than the sum of its proper divisors (254123613).

721681827 is a wasteful number, since it uses less digits than its factorization.

721681827 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4402.

The product of its digits is 75264, while the sum is 42.

The square root of 721681827 is about 26864.1364461990. The cubic root of 721681827 is about 896.9782721502.

The spelling of 721681827 in words is "seven hundred twenty-one million, six hundred eighty-one thousand, eight hundred twenty-seven".