390291681 has 8 divisors (see below), whose sum is σ = 560418880. Its totient is φ = 240179472.

The previous prime is 390291677. The next prime is 390291689. The reversal of 390291681 is 186192093.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 390291681 - 2² = 390291677 is a prime.

It is a super-2 number, since 2×390291681² = 304655192515611522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 10007479 = 390291681 / (3 + 9 + 0 + 2 + 9 + 1 + 6 + 8 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390291689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5003701 + ... + 5003778.

It is an arithmetic number, because the mean of its divisors is an integer number (70052360).

Almost surely, 2^390291681 is an apocalyptic number.

It is an amenable number.

390291681 is a deficient number, since it is larger than the sum of its proper divisors (170127199).

390291681 is a wasteful number, since it uses less digits than its factorization.

390291681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10007495.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 390291681 is about 19755.8011986353. The cubic root of 390291681 is about 730.7964541764.

The spelling of 390291681 in words is "three hundred ninety million, two hundred ninety-one thousand, six hundred eighty-one".