63665540 has 12 divisors (see below), whose sum is σ = 133697676. Its totient is φ = 25466208.

The previous prime is 63665531. The next prime is 63665549. The reversal of 63665540 is 4556636.

It is an interprime number because it is at equal distance from previous prime (63665531) and next prime (63665549).

It can be written as a sum of positive squares in 2 ways, for example, as 27857284 + 35808256 = 5278^2 + 5984^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 63665540.

It is not an unprimeable number, because it can be changed into a prime (63665549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1591619 + ... + 1591658.

It is an arithmetic number, because the mean of its divisors is an integer number (11141473).

Almost surely, 2^63665540 is an apocalyptic number.

It is an amenable number.

63665540 is an abundant number, since it is smaller than the sum of its proper divisors (70032136).

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

63665540 is a wasteful number, since it uses less digits than its factorization.

63665540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3183286 (or 3183284 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 35.

The square root of 63665540 is about 7979.0688679820. The cubic root of 63665540 is about 399.3019910004.

The spelling of 63665540 in words is "sixty-three million, six hundred sixty-five thousand, five hundred forty".