721112689 has 12 divisors (see below), whose sum is σ = 793280628. Its totient is φ = 655017440.

The previous prime is 721112683. The next prime is 721112699. The reversal of 721112689 is 986211127.

It can be written as a sum of positive squares in 2 ways, for example, as 567154225 + 153958464 = 23815^2 + 12408^2 .

It is not a de Polignac number, because 721112689 - 2⁵ = 721112657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721112683) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 266427 + ... + 269119.

It is an arithmetic number, because the mean of its divisors is an integer number (66106719).

Almost surely, 2^721112689 is an apocalyptic number.

It is an amenable number.

721112689 is a deficient number, since it is larger than the sum of its proper divisors (72167939).

721112689 is a wasteful number, since it uses less digits than its factorization.

721112689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4928 (or 4917 counting only the distinct ones).

The product of its digits is 12096, while the sum is 37.

The square root of 721112689 is about 26853.5414610438. The cubic root of 721112689 is about 896.7424162837.

It can be divided in two parts, 721112 and 689, that added together give a triangular number (721801 = T₁₂₀₁).

The spelling of 721112689 in words is "seven hundred twenty-one million, one hundred twelve thousand, six hundred eighty-nine".