19218845458849 has 4 divisors (see below), whose sum is σ = 19533908499220. Its totient is φ = 18903782418480.

The previous prime is 19218845458843. The next prime is 19218845458927. The reversal of 19218845458849 is 94885454881291.

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 3428911399824 + 15789934059025 = 1851732^2 + 3973655^2 .

It is a cyclic number.

It is not a de Polignac number, because 19218845458849 - 2⁴³ = 10422752436641 is a prime.

It is a super-2 number, since 2×19218845458849² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19218845458843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157531520094 + ... + 157531520215.

It is an arithmetic number, because the mean of its divisors is an integer number (4883477124805).

Almost surely, 2^{19218845458849} is an apocalyptic number.

It is an amenable number.

19218845458849 is a deficient number, since it is larger than the sum of its proper divisors (315063040371).

19218845458849 is an equidigital number, since it uses as much as digits as its factorization.

19218845458849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315063040370.

The product of its digits is 1061683200, while the sum is 76.

The spelling of 19218845458849 in words is "nineteen trillion, two hundred eighteen billion, eight hundred forty-five million, four hundred fifty-eight thousand, eight hundred forty-nine".