640106266 has 4 divisors (see below), whose sum is σ = 960159402. Its totient is φ = 320053132.

The previous prime is 640106237. The next prime is 640106279. The reversal of 640106266 is 662601046.

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., 595604025 + 44502241 = 24405^2 + 6671^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160026565 + ... + 160026568.

Almost surely, 2^640106266 is an apocalyptic number.

640106266 is a deficient number, since it is larger than the sum of its proper divisors (320053136).

640106266 is a wasteful number, since it uses less digits than its factorization.

640106266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320053135.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 640106266 is about 25300.3214604084. The cubic root of 640106266 is about 861.8215698641.

The spelling of 640106266 in words is "six hundred forty million, one hundred six thousand, two hundred sixty-six".