72447643 has 4 divisors (see below), whose sum is σ = 72514080. Its totient is φ = 72381208.

The previous prime is 72447623. The next prime is 72447653. The reversal of 72447643 is 34674427.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34674427 = 2179 ⋅15913.

It is a cyclic number.

It is not a de Polignac number, because 72447643 - 2⁵ = 72447611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72447623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31555 + ... + 33772.

It is an arithmetic number, because the mean of its divisors is an integer number (18128520).

Almost surely, 2^72447643 is an apocalyptic number.

72447643 is a deficient number, since it is larger than the sum of its proper divisors (66437).

72447643 is a wasteful number, since it uses less digits than its factorization.

72447643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66436.

The product of its digits is 112896, while the sum is 37.

The square root of 72447643 is about 8511.6181187833. The cubic root of 72447643 is about 416.8771459962.

The spelling of 72447643 in words is "seventy-two million, four hundred forty-seven thousand, six hundred forty-three".