640540563 has 32 divisors (see below), whose sum is σ = 940584960. Its totient is φ = 385307520.

The previous prime is 640540553. The next prime is 640540573. The reversal of 640540563 is 365045046.

It is an interprime number because it is at equal distance from previous prime (640540553) and next prime (640540573).

It is not a de Polignac number, because 640540563 - 2¹⁰ = 640539539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640540543) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 890518 + ... + 891236.

It is an arithmetic number, because the mean of its divisors is an integer number (29393280).

Almost surely, 2^640540563 is an apocalyptic number.

640540563 is a deficient number, since it is larger than the sum of its proper divisors (300044397).

640540563 is a wasteful number, since it uses less digits than its factorization.

640540563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1219.

The product of its (nonzero) digits is 43200, while the sum is 33.

The square root of 640540563 is about 25308.9028407001. The cubic root of 640540563 is about 862.0164343348.

The spelling of 640540563 in words is "six hundred forty million, five hundred forty thousand, five hundred sixty-three".