645415040266 has 4 divisors (see below), whose sum is σ = 968122560402. Its totient is φ = 322707520132.

The previous prime is 645415040243. The next prime is 645415040297. The reversal of 645415040266 is 662040514546.

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

It can be written as a sum of positive squares in only one way, i.e., 467622101241 + 177792939025 = 683829^2 + 421655^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161353760065 + ... + 161353760068.

Almost surely, 2^645415040266 is an apocalyptic number.

645415040266 is a deficient number, since it is larger than the sum of its proper divisors (322707520136).

645415040266 is a wasteful number, since it uses less digits than its factorization.

645415040266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322707520135.

The product of its (nonzero) digits is 691200, while the sum is 43.

The spelling of 645415040266 in words is "six hundred forty-five billion, four hundred fifteen million, forty thousand, two hundred sixty-six".