63681440 has 96 divisors (see below), whose sum is σ = 159957504. Its totient is φ = 23915520.

The previous prime is 63681437. The next prime is 63681467. The reversal of 63681440 is 4418636.

63681440 = T₄₂₄ + T₄₂₅ + ... + T₇₇₀.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 63681397 and 63681406.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183347 + ... + 183693.

It is an arithmetic number, because the mean of its divisors is an integer number (1666224).

Almost surely, 2^63681440 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 63681440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79978752).

63681440 is an abundant number, since it is smaller than the sum of its proper divisors (96276064).

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

63681440 is a wasteful number, since it uses less digits than its factorization.

63681440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 63681440 is about 7980.0651626412. The cubic root of 63681440 is about 399.3352291446.

The spelling of 63681440 in words is "sixty-three million, six hundred eighty-one thousand, four hundred forty".