640640155606 has 8 divisors (see below), whose sum is σ = 1048320254664. Its totient is φ = 291200070720.

The previous prime is 640640155583. The next prime is 640640155619. The reversal of 640640155606 is 606551046046.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14560003515 + ... + 14560003558.

It is an arithmetic number, because the mean of its divisors is an integer number (131040031833).

Almost surely, 2^640640155606 is an apocalyptic number.

640640155606 is a deficient number, since it is larger than the sum of its proper divisors (407680099058).

640640155606 is a wasteful number, since it uses less digits than its factorization.

640640155606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29120007086.

The product of its (nonzero) digits is 518400, while the sum is 43.

The spelling of 640640155606 in words is "six hundred forty billion, six hundred forty million, one hundred fifty-five thousand, six hundred six".