645182641085 has 4 divisors (see below), whose sum is σ = 774219169308. Its totient is φ = 516146112864.

The previous prime is 645182641079. The next prime is 645182641097. The reversal of 645182641085 is 580146281546.

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 316947606361 + 328235034724 = 562981^2 + 572918^2 .

It is a cyclic number.

It is not a de Polignac number, because 645182641085 - 2²⁶ = 645115532221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64518264104 + ... + 64518264113.

It is an arithmetic number, because the mean of its divisors is an integer number (193554792327).

Almost surely, 2^645182641085 is an apocalyptic number.

It is an amenable number.

645182641085 is a deficient number, since it is larger than the sum of its proper divisors (129036528223).

645182641085 is a wasteful number, since it uses less digits than its factorization.

645182641085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129036528222.

The product of its (nonzero) digits is 1843200, while the sum is 50.

The spelling of 645182641085 in words is "six hundred forty-five billion, one hundred eighty-two million, six hundred forty-one thousand, eighty-five".