72045840 has 40 divisors (see below), whose sum is σ = 223342848. Its totient is φ = 19212160.

The previous prime is 72045811. The next prime is 72045851. The reversal of 72045840 is 4854027.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×72045840² = 10381206122611200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 72045798 and 72045807.

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, 149856 + ... + 150335.

Almost surely, 2^72045840 is an apocalyptic number.

It is an amenable number.

72045840 is an abundant number, since it is smaller than the sum of its proper divisors (151297008).

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

72045840 is a wasteful number, since it uses less digits than its factorization.

72045840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300207 (or 300201 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 30.

The square root of 72045840 is about 8487.9820923468. The cubic root of 72045840 is about 416.1050338826.

Adding to 72045840 its reverse (4854027), we get a palindrome (76899867).

The spelling of 72045840 in words is "seventy-two million, forty-five thousand, eight hundred forty".