2581276981 has 2 divisors, whose sum is σ = 2581276982. Its totient is φ = 2581276980.

The previous prime is 2581276933. The next prime is 2581276987. The reversal of 2581276981 is 1896721852.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1673219025 + 908057956 = 40905^2 + 30134^2 .

It is a cyclic number.

It is not a de Polignac number, because 2581276981 - 2¹⁹ = 2580752693 is a prime.

It is a super-2 number, since 2×2581276981² = 13325981705280948722, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2581276987) 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, 1290638490 + 1290638491.

It is an arithmetic number, because the mean of its divisors is an integer number (1290638491).

Almost surely, 2^2581276981 is an apocalyptic number.

It is an amenable number.

2581276981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2581276981 is an equidigital number, since it uses as much as digits as its factorization.

2581276981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The square root of 2581276981 is about 50806.2691112032. The cubic root of 2581276981 is about 1371.7602147696.

The spelling of 2581276981 in words is "two billion, five hundred eighty-one million, two hundred seventy-six thousand, nine hundred eighty-one".