72017730 has 96 divisors (see below), whose sum is σ = 198722160. Its totient is φ = 18063360.

The previous prime is 72017711. The next prime is 72017773. The reversal of 72017730 is 3771027.

It can be written as a sum of positive squares in 8 ways, for example, as 8767521 + 63250209 = 2961^2 + 7953^2 .

It is a junction number, because it is equal to n+sod(n) for n = 72017694 and 72017703.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 106674 + ... + 107346.

Almost surely, 2^72017730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72017730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99361080).

72017730 is an abundant number, since it is smaller than the sum of its proper divisors (126704430).

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

72017730 is a wasteful number, since it uses less digits than its factorization.

72017730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756 (or 753 counting only the distinct ones).

The product of its (nonzero) digits is 2058, while the sum is 27.

The square root of 72017730 is about 8486.3260601983. The cubic root of 72017730 is about 416.0509098505.

Adding to 72017730 its reverse (3771027), we get a palindrome (75788757).

The spelling of 72017730 in words is "seventy-two million, seventeen thousand, seven hundred thirty".