645316265251 has 12 divisors (see below), whose sum is σ = 755169086448. Its totient is φ = 549816075312.

The previous prime is 645316265249. The next prime is 645316265257. The reversal of 645316265251 is 152562613546.

It is not a de Polignac number, because 645316265251 - 2¹ = 645316265249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645316265257) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39422116 + ... + 39438481.

It is an arithmetic number, because the mean of its divisors is an integer number (62930757204).

Almost surely, 2^645316265251 is an apocalyptic number.

645316265251 is a deficient number, since it is larger than the sum of its proper divisors (109852821197).

645316265251 is a wasteful number, since it uses less digits than its factorization.

645316265251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78860778 (or 78860771 counting only the distinct ones).

The product of its digits is 1296000, while the sum is 46.

Adding to 645316265251 its reverse (152562613546), we get a palindrome (797878878797).

The spelling of 645316265251 in words is "six hundred forty-five billion, three hundred sixteen million, two hundred sixty-five thousand, two hundred fifty-one".