645433511 has 4 divisors (see below), whose sum is σ = 648999624. Its totient is φ = 641867400.

The previous prime is 645433499. The next prime is 645433517. The reversal of 645433511 is 115334546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645433511 - 2⁶ = 645433447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645433517) 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, 1782785 + ... + 1783146.

It is an arithmetic number, because the mean of its divisors is an integer number (162249906).

Almost surely, 2^645433511 is an apocalyptic number.

645433511 is a deficient number, since it is larger than the sum of its proper divisors (3566113).

645433511 is a wasteful number, since it uses less digits than its factorization.

645433511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3566112.

The product of its digits is 21600, while the sum is 32.

The square root of 645433511 is about 25405.3835042890. The cubic root of 645433511 is about 864.2057868694.

The spelling of 645433511 in words is "six hundred forty-five million, four hundred thirty-three thousand, five hundred eleven".