390329981 has 8 divisors (see below), whose sum is σ = 394336800. Its totient is φ = 386331120.

The previous prime is 390329969. The next prime is 390329999. The reversal of 390329981 is 189923093.

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

It is a cyclic number.

It is not a de Polignac number, because 390329981 - 2⁶ = 390329917 is a prime.

It is a super-2 number, since 2×390329981² = 304714988134920722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390329081) 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 7 ways as a sum of consecutive naturals, for example, 165710 + ... + 168048.

It is an arithmetic number, because the mean of its divisors is an integer number (49292100).

Almost surely, 2^390329981 is an apocalyptic number.

It is an amenable number.

390329981 is a deficient number, since it is larger than the sum of its proper divisors (4006819).

390329981 is a wasteful number, since it uses less digits than its factorization.

390329981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3979.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 390329981 is about 19756.7705103845. The cubic root of 390329981 is about 730.8203581693.

The spelling of 390329981 in words is "three hundred ninety million, three hundred twenty-nine thousand, nine hundred eighty-one".