72145418 has 4 divisors (see below), whose sum is σ = 108218130. Its totient is φ = 36072708.

The previous prime is 72145397. The next prime is 72145427. The reversal of 72145418 is 81454127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81454127 = 29 ⋅2808763.

It can be written as a sum of positive squares in only one way, i.e., 70341769 + 1803649 = 8387^2 + 1343^2 .

It is a super-2 number, since 2×72145418² = 10409922676789448, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is an unprimeable number.

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, 18036353 + ... + 18036356.

Almost surely, 2^72145418 is an apocalyptic number.

72145418 is a deficient number, since it is larger than the sum of its proper divisors (36072712).

72145418 is a wasteful number, since it uses less digits than its factorization.

72145418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36072711.

The product of its digits is 8960, while the sum is 32.

The square root of 72145418 is about 8493.8458898193. The cubic root of 72145418 is about 416.2966518487.

The spelling of 72145418 in words is "seventy-two million, one hundred forty-five thousand, four hundred eighteen".