63981540 has 288 divisors, whose sum is σ = 245306880. Its totient is φ = 13160448.

The previous prime is 63981529. The next prime is 63981587. The reversal of 63981540 is 4518936.

63981540 is a `hidden beast` number, since 6 + 39 + 81 + 540 = 666.

63981540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 63981495 and 63981504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 621129 + ... + 621231.

It is an arithmetic number, because the mean of its divisors is an integer number (851760).

Almost surely, 2^63981540 is an apocalyptic number.

63981540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 63981540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122653440).

63981540 is an abundant number, since it is smaller than the sum of its proper divisors (181325340).

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

63981540 is a wasteful number, since it uses less digits than its factorization.

63981540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 63981540 is about 7998.8461667918. The cubic root of 63981540 is about 399.9615379685.

The spelling of 63981540 in words is "sixty-three million, nine hundred eighty-one thousand, five hundred forty".