72909072 has 100 divisors (see below), whose sum is σ = 213491916. Its totient is φ = 24019200.

The previous prime is 72909059. The next prime is 72909121. The reversal of 72909072 is 27090927.

It can be written as a sum of positive squares in 2 ways, for example, as 40144896 + 32764176 = 6336^2 + 5724^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 130618 + ... + 131174.

Almost surely, 2^72909072 is an apocalyptic number.

72909072 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72909072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106745958).

72909072 is an abundant number, since it is smaller than the sum of its proper divisors (140582844).

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

72909072 is a wasteful number, since it uses less digits than its factorization.

72909072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678 (or 663 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The square root of 72909072 is about 8538.6809285744. The cubic root of 72909072 is about 417.7603229047.

Adding to 72909072 its reverse (27090927), we get a palindrome (99999999).

The spelling of 72909072 in words is "seventy-two million, nine hundred nine thousand, seventy-two".