320211981 has 16 divisors (see below), whose sum is σ = 474707520. Its totient is φ = 213330960.

The previous prime is 320211971. The next prime is 320212001. The reversal of 320211981 is 189112023.

It is not a de Polignac number, because 320211981 - 2⁹ = 320211469 is a prime.

It is a super-2 number, since 2×320211981² = 205071425551888722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320211971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50266 + ... + 56276.

It is an arithmetic number, because the mean of its divisors is an integer number (29669220).

Almost surely, 2^320211981 is an apocalyptic number.

It is an amenable number.

320211981 is a deficient number, since it is larger than the sum of its proper divisors (154495539).

320211981 is a wasteful number, since it uses less digits than its factorization.

320211981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7993 (or 7987 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 320211981 is about 17894.4678881491. The cubic root of 320211981 is about 684.1413796705.

The spelling of 320211981 in words is "three hundred twenty million, two hundred eleven thousand, nine hundred eighty-one".