72428720 has 80 divisors (see below), whose sum is σ = 207278400. Its totient is φ = 22920192.

The previous prime is 72428717. The next prime is 72428723. The reversal of 72428720 is 2782427.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (72428717) and next prime (72428723).

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (72428723) 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, 2306 + ... + 12254.

It is an arithmetic number, because the mean of its divisors is an integer number (2590980).

Almost surely, 2^72428720 is an apocalyptic number.

72428720 is a gapful number since it is divisible by the number (70) 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 72428720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103639200).

72428720 is an abundant number, since it is smaller than the sum of its proper divisors (134849680).

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

72428720 is a wasteful number, since it uses less digits than its factorization.

72428720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9982 (or 9976 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 32.

The square root of 72428720 is about 8510.5064479148. The cubic root of 72428720 is about 416.8408473542.

The spelling of 72428720 in words is "seventy-two million, four hundred twenty-eight thousand, seven hundred twenty".