640254 has 16 divisors (see below), whose sum is σ = 1356048. Its totient is φ = 200832.

The previous prime is 640249. The next prime is 640259. The reversal of 640254 is 452046.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (640249) and next prime (640259).

It is a self number, because there is not a number n which added to its sum of digits gives 640254.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640254.

It is not an unprimeable number, because it can be changed into a prime (640259) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3037 + ... + 3240.

It is an arithmetic number, because the mean of its divisors is an integer number (84753).

2⁶⁴⁰²⁵⁴ is an apocalyptic number.

640254 is an abundant number, since it is smaller than the sum of its proper divisors (715794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640254 is a wasteful number, since it uses less digits than its factorization.

640254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6299.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 640254 is about 800.1587342521. The cubic root of 640254 is about 86.1887866436.

The spelling of 640254 in words is "six hundred forty thousand, two hundred fifty-four".