72326640 has 40 divisors (see below), whose sum is σ = 224213328. Its totient is φ = 19287040.

The previous prime is 72326621. The next prime is 72326641. The reversal of 72326640 is 4662327.

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

It is a super-2 number, since 2×72326640² = 10462285707379200, 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 = 72326598 and 72326607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72326641) 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, 150441 + ... + 150920.

Almost surely, 2^72326640 is an apocalyptic number.

It is an amenable number.

72326640 is an abundant number, since it is smaller than the sum of its proper divisors (151886688).

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

72326640 is a wasteful number, since it uses less digits than its factorization.

72326640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301377 (or 301371 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 30.

The square root of 72326640 is about 8504.5070403875. The cubic root of 72326640 is about 416.6449254434.

Adding to 72326640 its reverse (4662327), we get a palindrome (76988967).

The spelling of 72326640 in words is "seventy-two million, three hundred twenty-six thousand, six hundred forty".