390661680 has 120 divisors (see below), whose sum is σ = 1230738192. Its totient is φ = 102506496.

The previous prime is 390661589. The next prime is 390661681. The reversal of 390661680 is 86166093.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is not an unprimeable number, because it can be changed into a prime (390661681) 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 23 ways as a sum of consecutive naturals, for example, 2258074 + ... + 2258246.

Almost surely, 2^390661680 is an apocalyptic number.

390661680 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 390661680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (615369096).

390661680 is an abundant number, since it is smaller than the sum of its proper divisors (840076512).

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

390661680 is a wasteful number, since it uses less digits than its factorization.

390661680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383 (or 280 counting only the distinct ones).

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

The square root of 390661680 is about 19765.1632930264. The cubic root of 390661680 is about 731.0273144708.

The spelling of 390661680 in words is "three hundred ninety million, six hundred sixty-one thousand, six hundred eighty".