640214971 has 4 divisors (see below), whose sum is σ = 698416344. Its totient is φ = 582013600.

The previous prime is 640214963. The next prime is 640214977. The reversal of 640214971 is 179412046.

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

It is a cyclic number.

It is not a de Polignac number, because 640214971 - 2³ = 640214963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640214977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29100670 + ... + 29100691.

It is an arithmetic number, because the mean of its divisors is an integer number (174604086).

Almost surely, 2^640214971 is an apocalyptic number.

640214971 is a deficient number, since it is larger than the sum of its proper divisors (58201373).

640214971 is a wasteful number, since it uses less digits than its factorization.

640214971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58201372.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 640214971 is about 25302.4696620705. The cubic root of 640214971 is about 861.8703529157.

The spelling of 640214971 in words is "six hundred forty million, two hundred fourteen thousand, nine hundred seventy-one".