640333427 has 16 divisors (see below), whose sum is σ = 685670400. Its totient is φ = 596658720.

The previous prime is 640333417. The next prime is 640333453. The reversal of 640333427 is 724333046.

It is a cyclic number.

It is not a de Polignac number, because 640333427 - 2⁸ = 640333171 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640333393 and 640333402.

It is not an unprimeable number, because it can be changed into a prime (640333417) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 429878 + ... + 431364.

It is an arithmetic number, because the mean of its divisors is an integer number (42854400).

Almost surely, 2^640333427 is an apocalyptic number.

640333427 is a deficient number, since it is larger than the sum of its proper divisors (45336973).

640333427 is a wasteful number, since it uses less digits than its factorization.

640333427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2026.

The product of its (nonzero) digits is 36288, while the sum is 32.

The square root of 640333427 is about 25304.8103529744. The cubic root of 640333427 is about 861.9235055926.

The spelling of 640333427 in words is "six hundred forty million, three hundred thirty-three thousand, four hundred twenty-seven".