63866440 has 64 divisors (see below), whose sum is σ = 161040960. Its totient is φ = 22590720.

The previous prime is 63866419. The next prime is 63866443. The reversal of 63866440 is 4466836.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 63866440.

It is not an unprimeable number, because it can be changed into a prime (63866443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14319 + ... + 18241.

It is an arithmetic number, because the mean of its divisors is an integer number (2516265).

Almost surely, 2^63866440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 63866440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80520480).

63866440 is an abundant number, since it is smaller than the sum of its proper divisors (97174520).

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

63866440 is a wasteful number, since it uses less digits than its factorization.

63866440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3982 (or 3978 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 37.

The square root of 63866440 is about 7991.6481404026. The cubic root of 63866440 is about 399.7215562176.

The spelling of 63866440 in words is "sixty-three million, eight hundred sixty-six thousand, four hundred forty".