645231166 has 4 divisors (see below), whose sum is σ = 967846752. Its totient is φ = 322615582.

The previous prime is 645231161. The next prime is 645231187. The reversal of 645231166 is 661132546.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645231161) 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 as a sum of consecutive naturals, namely, 161307790 + ... + 161307793.

It is an arithmetic number, because the mean of its divisors is an integer number (241961688).

Almost surely, 2^645231166 is an apocalyptic number.

645231166 is a deficient number, since it is larger than the sum of its proper divisors (322615586).

645231166 is a wasteful number, since it uses less digits than its factorization.

645231166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322615585.

The product of its digits is 25920, while the sum is 34.

The square root of 645231166 is about 25401.4008668813. The cubic root of 645231166 is about 864.1154672140.

The spelling of 645231166 in words is "six hundred forty-five million, two hundred thirty-one thousand, one hundred sixty-six".