645356683 has 4 divisors (see below), whose sum is σ = 647653608. Its totient is φ = 643059760.

The previous prime is 645356659. The next prime is 645356689. The reversal of 645356683 is 386653546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 386653546 = 2 ⋅193326773.

It is a cyclic number.

It is not a de Polignac number, because 645356683 - 2⁵ = 645356651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645356689) 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, 1148041 + ... + 1148602.

It is an arithmetic number, because the mean of its divisors is an integer number (161913402).

Almost surely, 2^645356683 is an apocalyptic number.

645356683 is a deficient number, since it is larger than the sum of its proper divisors (2296925).

645356683 is a wasteful number, since it uses less digits than its factorization.

645356683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296924.

The product of its digits is 1555200, while the sum is 46.

The square root of 645356683 is about 25403.8714175615. The cubic root of 645356683 is about 864.1714957893.

It can be divided in two parts, 6453 and 56683, that added together give a palindrome (63136).

The spelling of 645356683 in words is "six hundred forty-five million, three hundred fifty-six thousand, six hundred eighty-three".