72345640 has 32 divisors (see below), whose sum is σ = 163192680. Its totient is φ = 28864512.

The previous prime is 72345631. The next prime is 72345641. The reversal of 72345640 is 4654327.

It can be written as a sum of positive squares in 4 ways, for example, as 59629284 + 12716356 = 7722^2 + 3566^2 .

It is not an unprimeable number, because it can be changed into a prime (72345641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15232 + ... + 19408.

Almost surely, 2^72345640 is an apocalyptic number.

It is an amenable number.

72345640 is an abundant number, since it is smaller than the sum of its proper divisors (90847040).

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

72345640 is a wasteful number, since it uses less digits than its factorization.

72345640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4621 (or 4617 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 72345640 is about 8505.6240217870. The cubic root of 72345640 is about 416.6814060564.

Adding to 72345640 its reverse (4654327), we get a palindrome (76999967).

The spelling of 72345640 in words is "seventy-two million, three hundred forty-five thousand, six hundred forty".