664448540 has 24 divisors (see below), whose sum is σ = 1594676832. Its totient is φ = 227810880.

The previous prime is 664448531. The next prime is 664448549. The reversal of 664448540 is 45844466.

It is an interprime number because it is at equal distance from previous prime (664448531) and next prime (664448549).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664448549) 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, 2372891 + ... + 2373170.

It is an arithmetic number, because the mean of its divisors is an integer number (66444868).

Almost surely, 2^664448540 is an apocalyptic number.

It is an amenable number.

664448540 is an abundant number, since it is smaller than the sum of its proper divisors (930228292).

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

664448540 is a wasteful number, since it uses less digits than its factorization.

664448540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4746077 (or 4746075 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 41.

The square root of 664448540 is about 25776.8993480597. The cubic root of 664448540 is about 872.6105321608.

The spelling of 664448540 in words is "six hundred sixty-four million, four hundred forty-eight thousand, five hundred forty".