640166201 has 4 divisors (see below), whose sum is σ = 640328052. Its totient is φ = 640004352.

The previous prime is 640166167. The next prime is 640166203. The reversal of 640166201 is 102661046.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 324180025 + 315986176 = 18005^2 + 17776^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640166201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640166203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74840 + ... + 82953.

It is an arithmetic number, because the mean of its divisors is an integer number (160082013).

Almost surely, 2^640166201 is an apocalyptic number.

It is an amenable number.

640166201 is a deficient number, since it is larger than the sum of its proper divisors (161851).

640166201 is a wasteful number, since it uses less digits than its factorization.

640166201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161850.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 640166201 is about 25301.5059037995. The cubic root of 640166201 is about 861.8484673063.

The spelling of 640166201 in words is "six hundred forty million, one hundred sixty-six thousand, two hundred one".