640553055 has 16 divisors (see below), whose sum is σ = 1025205984. Its totient is φ = 341521280.

The previous prime is 640553051. The next prime is 640553057. The reversal of 640553055 is 550355046.

It is not a de Polignac number, because 640553055 - 2² = 640553051 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640553051) 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, 74857 + ... + 82973.

It is an arithmetic number, because the mean of its divisors is an integer number (64075374).

Almost surely, 2^640553055 is an apocalyptic number.

640553055 is a deficient number, since it is larger than the sum of its proper divisors (384652929).

640553055 is a wasteful number, since it uses less digits than its factorization.

640553055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13386.

The product of its (nonzero) digits is 45000, while the sum is 33.

The square root of 640553055 is about 25309.1496301239. The cubic root of 640553055 is about 862.0220380597.

The spelling of 640553055 in words is "six hundred forty million, five hundred fifty-three thousand, fifty-five".