640261301566 has 8 divisors (see below), whose sum is σ = 961172128224. Its totient is φ = 319870592160.

The previous prime is 640261301513. The next prime is 640261301591. The reversal of 640261301566 is 665103162046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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, 130026235 + ... + 130031158.

It is an arithmetic number, because the mean of its divisors is an integer number (120146516028).

Almost surely, 2^640261301566 is an apocalyptic number.

640261301566 is a deficient number, since it is larger than the sum of its proper divisors (320910826658).

640261301566 is a wasteful number, since it uses less digits than its factorization.

640261301566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260058626.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 640261301566 in words is "six hundred forty billion, two hundred sixty-one million, three hundred one thousand, five hundred sixty-six".