72177728 has 56 divisors (see below), whose sum is σ = 166006272. Its totient is φ = 30495744.

The previous prime is 72177719. The next prime is 72177757. The reversal of 72177728 is 82777127.

It is a tau number, because it is divible by the number of its divisors (56).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31601 + ... + 33807.

Almost surely, 2^72177728 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 72177728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83003136).

72177728 is an abundant number, since it is smaller than the sum of its proper divisors (93828544).

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

72177728 is a wasteful number, since it uses less digits than its factorization.

72177728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2299 (or 2289 counting only the distinct ones).

The product of its digits is 76832, while the sum is 41.

The square root of 72177728 is about 8495.7476422031. The cubic root of 72177728 is about 416.3587880997.

The spelling of 72177728 in words is "seventy-two million, one hundred seventy-seven thousand, seven hundred twenty-eight".