645234873 has 4 divisors (see below), whose sum is σ = 860313168. Its totient is φ = 430156580.

The previous prime is 645234871. The next prime is 645234901. The reversal of 645234873 is 378432546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645234873 - 2¹ = 645234871 is a prime.

It is a super-2 number, since 2×645234873² = 832656082670652258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645234871) 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, 107539143 + ... + 107539148.

It is an arithmetic number, because the mean of its divisors is an integer number (215078292).

Almost surely, 2^645234873 is an apocalyptic number.

It is an amenable number.

645234873 is a deficient number, since it is larger than the sum of its proper divisors (215078295).

645234873 is a wasteful number, since it uses less digits than its factorization.

645234873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215078294.

The product of its digits is 483840, while the sum is 42.

The square root of 645234873 is about 25401.4738351931. The cubic root of 645234873 is about 864.1171220576.

It can be divided in two parts, 64523 and 4873, that added together give a palindrome (69396).

The spelling of 645234873 in words is "six hundred forty-five million, two hundred thirty-four thousand, eight hundred seventy-three".