721161788 has 12 divisors (see below), whose sum is σ = 1270504200. Its totient is φ = 358160592.

The previous prime is 721161781. The next prime is 721161797. The reversal of 721161788 is 887161127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721161781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 604406 + ... + 605597.

It is an arithmetic number, because the mean of its divisors is an integer number (105875350).

Almost surely, 2^721161788 is an apocalyptic number.

It is an amenable number.

721161788 is a deficient number, since it is larger than the sum of its proper divisors (549342412).

721161788 is a wasteful number, since it uses less digits than its factorization.

721161788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1210156 (or 1210154 counting only the distinct ones).

The product of its digits is 37632, while the sum is 41.

The square root of 721161788 is about 26854.4556451997. The cubic root of 721161788 is about 896.7627682377.

The spelling of 721161788 in words is "seven hundred twenty-one million, one hundred sixty-one thousand, seven hundred eighty-eight".