640734933499 has 4 divisors (see below), whose sum is σ = 642756179664. Its totient is φ = 638713687336.

The previous prime is 640734933491. The next prime is 640734933523. The reversal of 640734933499 is 994339437046.

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 640734933499 - 2³ = 640734933491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640734933491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1010622607 + ... + 1010623240.

It is an arithmetic number, because the mean of its divisors is an integer number (160689044916).

Almost surely, 2^640734933499 is an apocalyptic number.

640734933499 is a deficient number, since it is larger than the sum of its proper divisors (2021246165).

640734933499 is a wasteful number, since it uses less digits than its factorization.

640734933499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2021246164.

The product of its (nonzero) digits is 52907904, while the sum is 61.

The spelling of 640734933499 in words is "six hundred forty billion, seven hundred thirty-four million, nine hundred thirty-three thousand, four hundred ninety-nine".