331320655 has 4 divisors (see below), whose sum is σ = 397584792. Its totient is φ = 265056520.

The previous prime is 331320643. The next prime is 331320673. The reversal of 331320655 is 556023133.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 556023133 = 863 ⋅644291.

It is not a de Polignac number, because 331320655 - 2⁵ = 331320623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 33132061 + ... + 33132070.

It is an arithmetic number, because the mean of its divisors is an integer number (99396198).

Almost surely, 2^331320655 is an apocalyptic number.

331320655 is a deficient number, since it is larger than the sum of its proper divisors (66264137).

331320655 is an equidigital number, since it uses as much as digits as its factorization.

331320655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66264136.

The product of its (nonzero) digits is 8100, while the sum is 28.

The square root of 331320655 is about 18202.2156618363. The cubic root of 331320655 is about 691.9629429575.

Adding to 331320655 its reverse (556023133), we get a palindrome (887343788).

The spelling of 331320655 in words is "three hundred thirty-one million, three hundred twenty thousand, six hundred fifty-five".