20118869281 has 27 divisors (see below), whose sum is σ = 24493172403. Its totient is φ = 16476250560.

The previous prime is 20118869263. The next prime is 20118869297. The reversal of 20118869281 is 18296881102.

It is a happy number.

The square root of 20118869281 is 141841.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3529429281 + 16589440000 = 59409^2 + 128800^2 .

It is not a de Polignac number, because 20118869281 - 2⁷ = 20118869153 is a prime.

It is a super-2 number, since 2×20118869281² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20118869261) 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 in 26 ways as a sum of consecutive naturals, for example, 22835961 + ... + 22836841.

Almost surely, 2^20118869281 is an apocalyptic number.

20118869281 is the 141841-st square number.

20118869281 is the 70921-st centered octagonal number.

It is an amenable number.

20118869281 is a deficient number, since it is larger than the sum of its proper divisors (4374303122).

20118869281 is an frugal number, since it uses more digits than its factorization.

20118869281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1822 (or 911 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 46.

The spelling of 20118869281 in words is "twenty billion, one hundred eighteen million, eight hundred sixty-nine thousand, two hundred eighty-one".