72455818 has 4 divisors (see below), whose sum is σ = 108683730. Its totient is φ = 36227908.

The previous prime is 72455813. The next prime is 72455827. The reversal of 72455818 is 81855427.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81855427 = 6761 ⋅12107.

It can be written as a sum of positive squares in only one way, i.e., 51451929 + 21003889 = 7173^2 + 4583^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (72455813) 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 as a sum of consecutive naturals, namely, 18113953 + ... + 18113956.

Almost surely, 2^72455818 is an apocalyptic number.

72455818 is a deficient number, since it is larger than the sum of its proper divisors (36227912).

72455818 is a wasteful number, since it uses less digits than its factorization.

72455818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36227911.

The product of its digits is 89600, while the sum is 40.

The square root of 72455818 is about 8512.0983311990. The cubic root of 72455818 is about 416.8928255607.

The spelling of 72455818 in words is "seventy-two million, four hundred fifty-five thousand, eight hundred eighteen".