645577211 has 4 divisors (see below), whose sum is σ = 647640072. Its totient is φ = 643514352.

The previous prime is 645577187. The next prime is 645577241. The reversal of 645577211 is 112775546.

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 645577211 - 2²⁶ = 578468347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645577241) 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, 1030961 + ... + 1031586.

It is an arithmetic number, because the mean of its divisors is an integer number (161910018).

Almost surely, 2^645577211 is an apocalyptic number.

645577211 is a deficient number, since it is larger than the sum of its proper divisors (2062861).

645577211 is a wasteful number, since it uses less digits than its factorization.

645577211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2062860.

The product of its digits is 58800, while the sum is 38.

The square root of 645577211 is about 25408.2114876274. The cubic root of 645577211 is about 864.2699180073.

The spelling of 645577211 in words is "six hundred forty-five million, five hundred seventy-seven thousand, two hundred eleven".