721809112 has 8 divisors (see below), whose sum is σ = 1353392100. Its totient is φ = 360904552.

The previous prime is 721809089. The next prime is 721809119. The reversal of 721809112 is 211908127.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721809119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45113062 + ... + 45113077.

Almost surely, 2^721809112 is an apocalyptic number.

It is an amenable number.

721809112 is a deficient number, since it is larger than the sum of its proper divisors (631582988).

721809112 is a wasteful number, since it uses less digits than its factorization.

721809112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90226145 (or 90226141 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 721809112 is about 26866.5053924026. The cubic root of 721809112 is about 897.0310032216.

The spelling of 721809112 in words is "seven hundred twenty-one million, eight hundred nine thousand, one hundred twelve".