320536781 has 2 divisors, whose sum is σ = 320536782. Its totient is φ = 320536780.

The previous prime is 320536703. The next prime is 320536841. The reversal of 320536781 is 187635023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 320087881 + 448900 = 17891^2 + 670^2 .

It is a cyclic number.

It is not a de Polignac number, because 320536781 - 2²⁶ = 253427917 is a prime.

It is a super-2 number, since 2×320536781² = 205487655947683922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320530781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160268390 + 160268391.

It is an arithmetic number, because the mean of its divisors is an integer number (160268391).

Almost surely, 2^320536781 is an apocalyptic number.

It is an amenable number.

320536781 is a deficient number, since it is larger than the sum of its proper divisors (1).

320536781 is an equidigital number, since it uses as much as digits as its factorization.

320536781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 320536781 is about 17903.5410184689. The cubic root of 320536781 is about 684.3726161062.

The spelling of 320536781 in words is "three hundred twenty million, five hundred thirty-six thousand, seven hundred eighty-one".