72170730 has 32 divisors (see below), whose sum is σ = 192456000. Its totient is φ = 19245456.

The previous prime is 72170699. The next prime is 72170731. The reversal of 72170730 is 3707127.

It is a super-2 number, since 2×72170730² = 10417228537465800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 72170694 and 72170703.

It is not an unprimeable number, because it can be changed into a prime (72170731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133380 + ... + 133919.

It is an arithmetic number, because the mean of its divisors is an integer number (6014250).

Almost surely, 2^72170730 is an apocalyptic number.

72170730 is an abundant number, since it is smaller than the sum of its proper divisors (120285270).

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

72170730 is a wasteful number, since it uses less digits than its factorization.

72170730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267315 (or 267309 counting only the distinct ones).

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

The square root of 72170730 is about 8495.3357791202. The cubic root of 72170730 is about 416.3453316266.

Adding to 72170730 its reverse (3707127), we get a palindrome (75877857).

It can be divided in two parts, 72170 and 730, that added together give a square (72900 = 270²).

The spelling of 72170730 in words is "seventy-two million, one hundred seventy thousand, seven hundred thirty".