721164447 has 12 divisors (see below), whose sum is σ = 1069836040. Its totient is φ = 467782128.

The previous prime is 721164427. The next prime is 721164467. The reversal of 721164447 is 744461127.

It is a happy number.

721164447 is a `hidden beast` number, since 7 + 2 + 1 + 1 + 644 + 4 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (721164427) and next prime (721164467).

It is not a de Polignac number, because 721164447 - 2⁷ = 721164319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721164407) 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 11 ways as a sum of consecutive naturals, for example, 1082497 + ... + 1083162.

Almost surely, 2^721164447 is an apocalyptic number.

721164447 is a deficient number, since it is larger than the sum of its proper divisors (348671593).

721164447 is a wasteful number, since it uses less digits than its factorization.

721164447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2165702 (or 2165699 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The square root of 721164447 is about 26854.5051527672. The cubic root of 721164447 is about 896.7638703895.

The spelling of 721164447 in words is "seven hundred twenty-one million, one hundred sixty-four thousand, four hundred forty-seven".