645909495 has 48 divisors (see below), whose sum is σ = 1298250240. Its totient is φ = 268424640.

The previous prime is 645909491. The next prime is 645909497. The reversal of 645909495 is 594909546.

It is not a de Polignac number, because 645909495 - 2² = 645909491 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645909491) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12715 + ... + 38124.

It is an arithmetic number, because the mean of its divisors is an integer number (27046880).

Almost surely, 2^645909495 is an apocalyptic number.

645909495 is an abundant number, since it is smaller than the sum of its proper divisors (652340745).

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

645909495 is a wasteful number, since it uses less digits than its factorization.

645909495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50876 (or 50865 counting only the distinct ones).

The product of its (nonzero) digits is 1749600, while the sum is 51.

The square root of 645909495 is about 25414.7495561141. The cubic root of 645909495 is about 864.4181748968.

Adding to 645909495 its sum of digits (51), we get a palindrome (645909546).

The spelling of 645909495 in words is "six hundred forty-five million, nine hundred nine thousand, four hundred ninety-five".