18815252881 has 2 divisors, whose sum is σ = 18815252882. Its totient is φ = 18815252880.

The previous prime is 18815252857. The next prime is 18815252893. The reversal of 18815252881 is 18825251881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18691264656 + 123988225 = 136716^2 + 11135^2 .

It is a cyclic number.

It is not a de Polignac number, because 18815252881 - 2¹¹ = 18815250833 is a prime.

It is a super-2 number, since 2×18815252881² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18815252821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9407626440 + 9407626441.

It is an arithmetic number, because the mean of its divisors is an integer number (9407626441).

Almost surely, 2^18815252881 is an apocalyptic number.

It is an amenable number.

18815252881 is a deficient number, since it is larger than the sum of its proper divisors (1).

18815252881 is an equidigital number, since it uses as much as digits as its factorization.

18815252881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 409600, while the sum is 49.

The spelling of 18815252881 in words is "eighteen billion, eight hundred fifteen million, two hundred fifty-two thousand, eight hundred eighty-one".