63645940 has 24 divisors (see below), whose sum is σ = 136918152. Its totient is φ = 24837120.

The previous prime is 63645929. The next prime is 63645949. The reversal of 63645940 is 4954636.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 729316 + 62916624 = 854^2 + 7932^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 63645940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63645949) 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, 37989 + ... + 39628.

It is an arithmetic number, because the mean of its divisors is an integer number (5704923).

Almost surely, 2^63645940 is an apocalyptic number.

It is an amenable number.

63645940 is an abundant number, since it is smaller than the sum of its proper divisors (73272212).

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

63645940 is a wasteful number, since it uses less digits than its factorization.

63645940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77667 (or 77665 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 63645940 is about 7977.8405599510. The cubic root of 63645940 is about 399.2610105773.

The spelling of 63645940 in words is "sixty-three million, six hundred forty-five thousand, nine hundred forty".