645736637546 has 96 divisors (see below), whose sum is σ = 1310952867840. Its totient is φ = 232127343360.

The previous prime is 645736637543. The next prime is 645736637593.

645736637546 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (645736637543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 61149815 + ... + 61160373.

It is an arithmetic number, because the mean of its divisors is an integer number (13655759040).

Almost surely, 2^645736637546 is an apocalyptic number.

645736637546 is an abundant number, since it is smaller than the sum of its proper divisors (665216230294).

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

645736637546 is a wasteful number, since it uses less digits than its factorization.

645736637546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13380 (or 13369 counting only the distinct ones).

The product of its digits is 228614400, while the sum is 62.

The spelling of 645736637546 in words is "six hundred forty-five billion, seven hundred thirty-six million, six hundred thirty-seven thousand, five hundred forty-six".