72157045 has 4 divisors (see below), whose sum is σ = 86588460. Its totient is φ = 57725632.

The previous prime is 72157037. The next prime is 72157073. The reversal of 72157045 is 54075127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54075127 = 5077 ⋅10651.

It can be written as a sum of positive squares in 2 ways, for example, as 15952036 + 56205009 = 3994^2 + 7497^2 .

It is a cyclic number.

It is not a de Polignac number, because 72157045 - 2³ = 72157037 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 72156998 and 72157016.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7215700 + ... + 7215709.

It is an arithmetic number, because the mean of its divisors is an integer number (21647115).

Almost surely, 2^72157045 is an apocalyptic number.

It is an amenable number.

72157045 is a deficient number, since it is larger than the sum of its proper divisors (14431415).

72157045 is a wasteful number, since it uses less digits than its factorization.

72157045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14431414.

The product of its (nonzero) digits is 9800, while the sum is 31.

The square root of 72157045 is about 8494.5302989630. The cubic root of 72157045 is about 416.3190141891.

The spelling of 72157045 in words is "seventy-two million, one hundred fifty-seven thousand, forty-five".