640507133 has 4 divisors (see below), whose sum is σ = 732008160. Its totient is φ = 549006108.

The previous prime is 640507129. The next prime is 640507163. The reversal of 640507133 is 331705046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 331705046 = 2 ⋅165852523.

It is not a de Polignac number, because 640507133 - 2² = 640507129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640507096 and 640507105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640507103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45750503 + ... + 45750516.

It is an arithmetic number, because the mean of its divisors is an integer number (183002040).

Almost surely, 2^640507133 is an apocalyptic number.

It is an amenable number.

640507133 is a deficient number, since it is larger than the sum of its proper divisors (91501027).

640507133 is an equidigital number, since it uses as much as digits as its factorization.

640507133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91501026.

The product of its (nonzero) digits is 7560, while the sum is 29.

The square root of 640507133 is about 25308.2423925487. The cubic root of 640507133 is about 862.0014377770.

The spelling of 640507133 in words is "six hundred forty million, five hundred seven thousand, one hundred thirty-three".