63646740 has 72 divisors (see below), whose sum is σ = 193808160. Its totient is φ = 16906944.

The previous prime is 63646733. The next prime is 63646741. The reversal of 63646740 is 4764636.

63646740 is a `hidden beast` number, since 6 + 3 + 646 + 7 + 4 + 0 = 666.

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 = 63646695 and 63646704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63646741) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61951 + ... + 62969.

It is an arithmetic number, because the mean of its divisors is an integer number (2691780).

Almost surely, 2^63646740 is an apocalyptic number.

63646740 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 63646740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96904080).

63646740 is an abundant number, since it is smaller than the sum of its proper divisors (130161420).

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

63646740 is a wasteful number, since it uses less digits than its factorization.

63646740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1381 (or 1376 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 63646740 is about 7977.8906986747. The cubic root of 63646740 is about 399.2626834124.

The spelling of 63646740 in words is "sixty-three million, six hundred forty-six thousand, seven hundred forty".