63731640 has 128 divisors (see below), whose sum is σ = 231413760. Its totient is φ = 13707264.

The previous prime is 63731627. The next prime is 63731651. The reversal of 63731640 is 4613736.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 63731598 and 63731607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12049 + ... + 16511.

It is an arithmetic number, because the mean of its divisors is an integer number (1807920).

Almost surely, 2^63731640 is an apocalyptic number.

63731640 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 63731640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115706880).

63731640 is an abundant number, since it is smaller than the sum of its proper divisors (167682120).

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

63731640 is a wasteful number, since it uses less digits than its factorization.

63731640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4501 (or 4497 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 30.

The square root of 63731640 is about 7983.2098807435. The cubic root of 63731640 is about 399.4401334058.

The spelling of 63731640 in words is "sixty-three million, seven hundred thirty-one thousand, six hundred forty".