645494957 has 4 divisors (see below), whose sum is σ = 645582336. Its totient is φ = 645407580.

The previous prime is 645494929. The next prime is 645494959. The reversal of 645494957 is 759494546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645494957 - 2⁶ = 645494893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645494899 and 645494908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645494959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31469 + ... + 47762.

It is an arithmetic number, because the mean of its divisors is an integer number (161395584).

Almost surely, 2^645494957 is an apocalyptic number.

It is an amenable number.

645494957 is a deficient number, since it is larger than the sum of its proper divisors (87379).

645494957 is an equidigital number, since it uses as much as digits as its factorization.

645494957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87378.

The product of its digits is 5443200, while the sum is 53.

The square root of 645494957 is about 25406.5927861254. The cubic root of 645494957 is about 864.2332104552.

The spelling of 645494957 in words is "six hundred forty-five million, four hundred ninety-four thousand, nine hundred fifty-seven".