320520981 has 16 divisors (see below), whose sum is σ = 474117120. Its totient is φ = 190961520.

The previous prime is 320520923. The next prime is 320521001. The reversal of 320520981 is 189025023.

It is a happy number.

It is not a de Polignac number, because 320520981 - 2⁹ = 320520469 is a prime.

It is a super-2 number, since 2×320520981² = 205467398522404722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320520181) 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 15 ways as a sum of consecutive naturals, for example, 80365 + ... + 84258.

It is an arithmetic number, because the mean of its divisors is an integer number (29632320).

Almost surely, 2^320520981 is an apocalyptic number.

It is an amenable number.

320520981 is a deficient number, since it is larger than the sum of its proper divisors (153596139).

320520981 is a wasteful number, since it uses less digits than its factorization.

320520981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164696.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 320520981 is about 17903.0997595388. The cubic root of 320520981 is about 684.3613711512.

The spelling of 320520981 in words is "three hundred twenty million, five hundred twenty thousand, nine hundred eighty-one".