399260661 has 16 divisors (see below), whose sum is σ = 579691200. Its totient is φ = 243468288.

The previous prime is 399260639. The next prime is 399260663. The reversal of 399260661 is 166062993.

It is not a de Polignac number, because 399260661 - 2¹⁵ = 399227893 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399260663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119116 + ... + 122421.

It is an arithmetic number, because the mean of its divisors is an integer number (36230700).

Almost surely, 2^399260661 is an apocalyptic number.

It is an amenable number.

399260661 is a deficient number, since it is larger than the sum of its proper divisors (180430539).

399260661 is a wasteful number, since it uses less digits than its factorization.

399260661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241588.

The product of its (nonzero) digits is 104976, while the sum is 42.

The square root of 399260661 is about 19981.5079761263. The cubic root of 399260661 is about 736.3520617224.

The spelling of 399260661 in words is "three hundred ninety-nine million, two hundred sixty thousand, six hundred sixty-one".