645291138263 has 4 divisors (see below), whose sum is σ = 645339246720. Its totient is φ = 645243029808.

The previous prime is 645291138259. The next prime is 645291138277. The reversal of 645291138263 is 362831192546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 362831192546 = 2 ⋅181415596273.

It is a cyclic number.

It is not a de Polignac number, because 645291138263 - 2² = 645291138259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645291138293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24034103 + ... + 24060936.

It is an arithmetic number, because the mean of its divisors is an integer number (161334811680).

Almost surely, 2^645291138263 is an apocalyptic number.

645291138263 is a deficient number, since it is larger than the sum of its proper divisors (48108457).

645291138263 is a wasteful number, since it uses less digits than its factorization.

645291138263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48108456.

The product of its digits is 1866240, while the sum is 50.

The spelling of 645291138263 in words is "six hundred forty-five billion, two hundred ninety-one million, one hundred thirty-eight thousand, two hundred sixty-three".