645818011 has 4 divisors (see below), whose sum is σ = 646055352. Its totient is φ = 645580672.

The previous prime is 645818003. The next prime is 645818027. The reversal of 645818011 is 110818546.

It is a happy number.

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 645818011 - 2³ = 645818003 is a prime.

It is a super-2 number, since 2×645818011² = 834161806663992242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645818611) 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, 114541 + ... + 120046.

It is an arithmetic number, because the mean of its divisors is an integer number (161513838).

Almost surely, 2^645818011 is an apocalyptic number.

645818011 is a deficient number, since it is larger than the sum of its proper divisors (237341).

645818011 is a wasteful number, since it uses less digits than its factorization.

645818011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237340.

The product of its (nonzero) digits is 7680, while the sum is 34.

The square root of 645818011 is about 25412.9496713782. The cubic root of 645818011 is about 864.3773620756.

The spelling of 645818011 in words is "six hundred forty-five million, eight hundred eighteen thousand, eleven".