39661680 has 80 divisors (see below), whose sum is σ = 130197024. Its totient is φ = 9953280.

The previous prime is 39661639. The next prime is 39661681. The reversal of 39661680 is 8616693.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39661681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 781 + ... + 8940.

Almost surely, 2^39661680 is an apocalyptic number.

39661680 is a gapful number since it is divisible by the number (30) 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 39661680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65098512).

39661680 is an abundant number, since it is smaller than the sum of its proper divisors (90535344).

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

39661680 is a wasteful number, since it uses less digits than its factorization.

39661680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9754 (or 9748 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 39661680 is about 6297.7519798735. The cubic root of 39661680 is about 341.0282596555.

The spelling of 39661680 in words is "thirty-nine million, six hundred sixty-one thousand, six hundred eighty".