645880507836 has 24 divisors (see below), whose sum is σ = 1518558754944. Its totient is φ = 213650040240.

The previous prime is 645880507823. The next prime is 645880507843. The reversal of 645880507836 is 638705088546.

It is a self number, because there is not a number n which added to its sum of digits gives 645880507836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 205431160 + ... + 205434303.

It is an arithmetic number, because the mean of its divisors is an integer number (63273281456).

Almost surely, 2^645880507836 is an apocalyptic number.

It is an amenable number.

645880507836 is an abundant number, since it is smaller than the sum of its proper divisors (872678247108).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645880507836 is a wasteful number, since it uses less digits than its factorization.

645880507836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410865601 (or 410865599 counting only the distinct ones).

The product of its (nonzero) digits is 38707200, while the sum is 60.

The spelling of 645880507836 in words is "six hundred forty-five billion, eight hundred eighty million, five hundred seven thousand, eight hundred thirty-six".