640148326831 has 4 divisors (see below), whose sum is σ = 689390505832. Its totient is φ = 590906147832.

The previous prime is 640148326823. The next prime is 640148326841. The reversal of 640148326831 is 138623841046.

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

It is not a de Polignac number, because 640148326831 - 2³ = 640148326823 is a prime.

It is a super-2 number, since 2×640148326831² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640148326841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24621089481 + ... + 24621089506.

It is an arithmetic number, because the mean of its divisors is an integer number (172347626458).

Almost surely, 2^640148326831 is an apocalyptic number.

640148326831 is a deficient number, since it is larger than the sum of its proper divisors (49242179001).

640148326831 is a wasteful number, since it uses less digits than its factorization.

640148326831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49242179000.

The product of its (nonzero) digits is 663552, while the sum is 46.

The spelling of 640148326831 in words is "six hundred forty billion, one hundred forty-eight million, three hundred twenty-six thousand, eight hundred thirty-one".