2151318581 has 2 divisors, whose sum is σ = 2151318582. Its totient is φ = 2151318580.

The previous prime is 2151318577. The next prime is 2151318619. The reversal of 2151318581 is 1858131512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1337072356 + 814246225 = 36566^2 + 28535^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151318581 - 2² = 2151318577 is a prime.

It is a super-2 number, since 2×2151318581² = 9256343273911707122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2151318881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075659290 + 1075659291.

It is an arithmetic number, because the mean of its divisors is an integer number (1075659291).

Almost surely, 2^2151318581 is an apocalyptic number.

It is an amenable number.

2151318581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151318581 is an equidigital number, since it uses as much as digits as its factorization.

2151318581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9600, while the sum is 35.

The square root of 2151318581 is about 46382.3089226916. The cubic root of 2151318581 is about 1290.9266784664.

The spelling of 2151318581 in words is "two billion, one hundred fifty-one million, three hundred eighteen thousand, five hundred eighty-one".