640136383 has 4 divisors (see below), whose sum is σ = 640292400. Its totient is φ = 639980368.

The previous prime is 640136351. The next prime is 640136389. The reversal of 640136383 is 383631046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 383631046 = 2 ⋅191815523.

It is a cyclic number.

It is not a de Polignac number, because 640136383 - 2⁵ = 640136351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640136389) 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, 71683 + ... + 80116.

It is an arithmetic number, because the mean of its divisors is an integer number (160073100).

Almost surely, 2^640136383 is an apocalyptic number.

640136383 is a deficient number, since it is larger than the sum of its proper divisors (156017).

640136383 is a wasteful number, since it uses less digits than its factorization.

640136383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156016.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 640136383 is about 25300.9166434736. The cubic root of 640136383 is about 861.8350858872.

The spelling of 640136383 in words is "six hundred forty million, one hundred thirty-six thousand, three hundred eighty-three".