72251440 has 20 divisors (see below), whose sum is σ = 167984784. Its totient is φ = 28900544.

The previous prime is 72251419. The next prime is 72251447. The reversal of 72251440 is 4415227.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-3 number, since 3×72251440³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (72251447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451492 + ... + 451651.

Almost surely, 2^72251440 is an apocalyptic number.

It is an amenable number.

72251440 is an abundant number, since it is smaller than the sum of its proper divisors (95733344).

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

72251440 is a wasteful number, since it uses less digits than its factorization.

72251440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903156 (or 903150 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 72251440 is about 8500.0847054603. The cubic root of 72251440 is about 416.5004763004.

Adding to 72251440 its reverse (4415227), we get a palindrome (76666667).

The spelling of 72251440 in words is "seventy-two million, two hundred fifty-one thousand, four hundred forty".