721765000 has 120 divisors (see below), whose sum is σ = 1860365430. Its totient is φ = 262240000.

The previous prime is 721764983. The next prime is 721765007. The reversal of 721765000 is 567127.

It can be written as a sum of positive squares in 5 ways, for example, as 9622404 + 712142596 = 3102^2 + 26686^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 721765000.

It is not an unprimeable number, because it can be changed into a prime (721765007) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 604404 + ... + 605596.

Almost surely, 2^721765000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721765000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930182715).

721765000 is an abundant number, since it is smaller than the sum of its proper divisors (1138600430).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721765000 is a wasteful number, since it uses less digits than its factorization.

721765000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241 (or 1211 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 721765000 is about 26865.6844320036. The cubic root of 721765000 is about 897.0127293977.

The spelling of 721765000 in words is "seven hundred twenty-one million, seven hundred sixty-five thousand".