645738706 has 4 divisors (see below), whose sum is σ = 968608062. Its totient is φ = 322869352.

The previous prime is 645738673. The next prime is 645738707. The reversal of 645738706 is 607837546.

645738706 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 484220025 + 161518681 = 22005^2 + 12709^2 .

It is not an unprimeable number, because it can be changed into a prime (645738707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161434675 + ... + 161434678.

Almost surely, 2^645738706 is an apocalyptic number.

645738706 is a deficient number, since it is larger than the sum of its proper divisors (322869356).

645738706 is a wasteful number, since it uses less digits than its factorization.

645738706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322869355.

The product of its (nonzero) digits is 846720, while the sum is 46.

The square root of 645738706 is about 25411.3892969275. The cubic root of 645738706 is about 864.3419794282.

The spelling of 645738706 in words is "six hundred forty-five million, seven hundred thirty-eight thousand, seven hundred six".