640442159 has 16 divisors (see below), whose sum is σ = 738865920. Its totient is φ = 543775680.

The previous prime is 640442147. The next prime is 640442167. The reversal of 640442159 is 951244046.

It is not a de Polignac number, because 640442159 - 2⁸ = 640441903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640442059) 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 15 ways as a sum of consecutive naturals, for example, 431699 + ... + 433179.

It is an arithmetic number, because the mean of its divisors is an integer number (46179120).

Almost surely, 2^640442159 is an apocalyptic number.

640442159 is a deficient number, since it is larger than the sum of its proper divisors (98423761).

640442159 is a wasteful number, since it uses less digits than its factorization.

640442159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2030.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 640442159 is about 25306.9587070434. The cubic root of 640442159 is about 861.9722892203.

The spelling of 640442159 in words is "six hundred forty million, four hundred forty-two thousand, one hundred fifty-nine".