18912961489 has 4 divisors (see below), whose sum is σ = 19223010100. Its totient is φ = 18602912880.

The previous prime is 18912961481. The next prime is 18912961493. The reversal of 18912961489 is 98416921981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9172850625 + 9740110864 = 95775^2 + 98692^2 .

It is a cyclic number.

It is not a de Polignac number, because 18912961489 - 2³ = 18912961481 is a prime.

It is a super-2 number, since 2×18912961489² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18912961481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155024214 + ... + 155024335.

It is an arithmetic number, because the mean of its divisors is an integer number (4805752525).

Almost surely, 2^18912961489 is an apocalyptic number.

It is an amenable number.

18912961489 is a deficient number, since it is larger than the sum of its proper divisors (310048611).

18912961489 is an equidigital number, since it uses as much as digits as its factorization.

18912961489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310048610.

The product of its digits is 2239488, while the sum is 58.

The spelling of 18912961489 in words is "eighteen billion, nine hundred twelve million, nine hundred sixty-one thousand, four hundred eighty-nine".