63555840 has 180 divisors, whose sum is σ = 227785404. Its totient is φ = 16920576.

The previous prime is 63555827. The next prime is 63555847. The reversal of 63555840 is 4855536.

63555840 is a `hidden beast` number, since 63 + 5 + 558 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7485696 + 56070144 = 2736^2 + 7488^2 .

It is a tau number, because it is divible by the number of its divisors (180).

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 = 63555795 and 63555804.

It is not an unprimeable number, because it can be changed into a prime (63555847) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 103374 + ... + 103986.

Almost surely, 2^63555840 is an apocalyptic number.

63555840 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 63555840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113892702).

63555840 is an abundant number, since it is smaller than the sum of its proper divisors (164229564).

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

63555840 is an equidigital number, since it uses as much as digits as its factorization.

63555840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The square root of 63555840 is about 7972.1916685439. The cubic root of 63555840 is about 399.0725177706.

The spelling of 63555840 in words is "sixty-three million, five hundred fifty-five thousand, eight hundred forty".