390631661 has 16 divisors (see below), whose sum is σ = 475891200. Its totient is φ = 313002240.

The previous prime is 390631643. The next prime is 390631663. The reversal of 390631661 is 166136093.

It is a cyclic number.

It is not a de Polignac number, because 390631661 - 2⁶ = 390631597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390631663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6716 + ... + 28746.

It is an arithmetic number, because the mean of its divisors is an integer number (29743200).

Almost surely, 2^390631661 is an apocalyptic number.

It is an amenable number.

390631661 is a deficient number, since it is larger than the sum of its proper divisors (85259539).

390631661 is a wasteful number, since it uses less digits than its factorization.

390631661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22204.

The product of its (nonzero) digits is 17496, while the sum is 35.

The square root of 390631661 is about 19764.4038867860. The cubic root of 390631661 is about 731.0085895978.

The spelling of 390631661 in words is "three hundred ninety million, six hundred thirty-one thousand, six hundred sixty-one".