640201266 has 32 divisors (see below), whose sum is σ = 1506358080. Its totient is φ = 200847168.

The previous prime is 640201231. The next prime is 640201279. The reversal of 640201266 is 662102046.

It is a happy number.

640201266 is a `hidden beast` number, since 640 + 2 + 0 + 12 + 6 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 347776 + ... + 349611.

It is an arithmetic number, because the mean of its divisors is an integer number (47073690).

Almost surely, 2^640201266 is an apocalyptic number.

640201266 is an abundant number, since it is smaller than the sum of its proper divisors (866156814).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640201266 is a wasteful number, since it uses less digits than its factorization.

640201266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697415 (or 697409 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 640201266 is about 25302.1988372552. The cubic root of 640201266 is about 861.8642028890.

The spelling of 640201266 in words is "six hundred forty million, two hundred one thousand, two hundred sixty-six".