320251681 has 4 divisors (see below), whose sum is σ = 321469632. Its totient is φ = 319033732.

The previous prime is 320251651. The next prime is 320251703. The reversal of 320251681 is 186152023.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 320251681 - 2⁵ = 320251649 is a prime.

It is a super-2 number, since 2×320251681² = 205122278366651522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (320251601) 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 3 ways as a sum of consecutive naturals, for example, 608581 + ... + 609106.

It is an arithmetic number, because the mean of its divisors is an integer number (80367408).

Almost surely, 2^320251681 is an apocalyptic number.

It is an amenable number.

320251681 is a deficient number, since it is larger than the sum of its proper divisors (1217951).

320251681 is a wasteful number, since it uses less digits than its factorization.

320251681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217950.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 320251681 is about 17895.5771351471. The cubic root of 320251681 is about 684.1696518693.

The spelling of 320251681 in words is "three hundred twenty million, two hundred fifty-one thousand, six hundred eighty-one".