645516490423 has 6 divisors (see below), whose sum is σ = 750906937896. Its totient is φ = 553299848892.

The previous prime is 645516490391. The next prime is 645516490427. The reversal of 645516490423 is 324094615546.

It is not a de Polignac number, because 645516490423 - 2⁵ = 645516490391 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 13173805927 = 645516490423 / (6 + 4 + 5 + 5 + 1 + 6 + 4 + 9 + 0 + 4 + 2 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645516490427) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6586902915 + ... + 6586903012.

It is an arithmetic number, because the mean of its divisors is an integer number (125151156316).

Almost surely, 2^645516490423 is an apocalyptic number.

645516490423 is a deficient number, since it is larger than the sum of its proper divisors (105390447473).

645516490423 is a wasteful number, since it uses less digits than its factorization.

645516490423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13173805941 (or 13173805934 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 49.

The spelling of 645516490423 in words is "six hundred forty-five billion, five hundred sixteen million, four hundred ninety thousand, four hundred twenty-three".