2513251981 has 2 divisors, whose sum is σ = 2513251982. Its totient is φ = 2513251980.

The previous prime is 2513251927. The next prime is 2513251991. The reversal of 2513251981 is 1891523152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2414149956 + 99102025 = 49134^2 + 9955^2 .

It is a cyclic number.

It is not a de Polignac number, because 2513251981 - 2¹¹ = 2513249933 is a prime.

It is a super-2 number, since 2×2513251981² = 12632871040000848722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2513251981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2513251921) 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, 1256625990 + 1256625991.

It is an arithmetic number, because the mean of its divisors is an integer number (1256625991).

Almost surely, 2^2513251981 is an apocalyptic number.

It is an amenable number.

2513251981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2513251981 is an equidigital number, since it uses as much as digits as its factorization.

2513251981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21600, while the sum is 37.

The square root of 2513251981 is about 50132.3446589126. The cubic root of 2513251981 is about 1359.6026775110.

The spelling of 2513251981 in words is "two billion, five hundred thirteen million, two hundred fifty-one thousand, nine hundred eighty-one".