815072645 has 4 divisors (see below), whose sum is σ = 978087180. Its totient is φ = 652058112.

The previous prime is 815072623. The next prime is 815072651. The reversal of 815072645 is 546270518.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 157201444 + 657871201 = 12538^2 + 25649^2 .

It is a cyclic number.

It is not a de Polignac number, because 815072645 - 2²⁰ = 814024069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 815072599 and 815072608.

It is a congruent 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 in 3 ways as a sum of consecutive naturals, for example, 81507260 + ... + 81507269.

It is an arithmetic number, because the mean of its divisors is an integer number (244521795).

Almost surely, 2^815072645 is an apocalyptic number.

It is an amenable number.

815072645 is a deficient number, since it is larger than the sum of its proper divisors (163014535).

815072645 is a wasteful number, since it uses less digits than its factorization.

815072645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163014534.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 815072645 is about 28549.4771405712. The cubic root of 815072645 is about 934.1116157819. Note that the first 3 decimals are identical.

The spelling of 815072645 in words is "eight hundred fifteen million, seventy-two thousand, six hundred forty-five".