2256331981 has 2 divisors, whose sum is σ = 2256331982. Its totient is φ = 2256331980.

The previous prime is 2256331949. The next prime is 2256331997. The reversal of 2256331981 is 1891336522.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2179489225 + 76842756 = 46685^2 + 8766^2 .

It is a cyclic number.

It is not a de Polignac number, because 2256331981 - 2⁵ = 2256331949 is a prime.

It is a super-2 number, since 2×2256331981² = 10182068016966768722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2256331481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1128165990 + 1128165991.

It is an arithmetic number, because the mean of its divisors is an integer number (1128165991).

Almost surely, 2^2256331981 is an apocalyptic number.

It is an amenable number.

2256331981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2256331981 is an equidigital number, since it uses as much as digits as its factorization.

2256331981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 40.

The square root of 2256331981 is about 47500.8629500560. The cubic root of 2256331981 is about 1311.5987668968.

The spelling of 2256331981 in words is "two billion, two hundred fifty-six million, three hundred thirty-one thousand, nine hundred eighty-one".