645732611 has 4 divisors (see below), whose sum is σ = 646142112. Its totient is φ = 645323112.

The previous prime is 645732583. The next prime is 645732653. The reversal of 645732611 is 116237546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 116237546 = 2 ⋅58118773.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645732611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645732691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202376 + ... + 205541.

It is an arithmetic number, because the mean of its divisors is an integer number (161535528).

Almost surely, 2^645732611 is an apocalyptic number.

645732611 is a deficient number, since it is larger than the sum of its proper divisors (409501).

645732611 is a wasteful number, since it uses less digits than its factorization.

645732611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409500.

The product of its digits is 30240, while the sum is 35.

The square root of 645732611 is about 25411.2693701043. The cubic root of 645732611 is about 864.3392599687.

The spelling of 645732611 in words is "six hundred forty-five million, seven hundred thirty-two thousand, six hundred eleven".