19814151813481 has 3 divisors (see below), whose sum is σ = 19814156264791. Its totient is φ = 19814147362172.

The previous prime is 19814151813403. The next prime is 19814151813527. The reversal of 19814151813481 is 18431815141891.

The square root of 19814151813481 is 4451309.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 17513044849881 + 2301106963600 = 4184859^2 + 1516940^2 .

It is not a de Polignac number, because 19814151813481 - 2⁷ = 19814151813353 is a prime.

It is a super-3 number, since 3×19814151813481³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19814151813581) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2225655 + ... + 6676963.

Almost surely, 2^{19814151813481} is an apocalyptic number.

19814151813481 is the 4451309-th square number.

19814151813481 is the 2225655-th centered octagonal number.

It is an amenable number.

19814151813481 is a deficient number, since it is larger than the sum of its proper divisors (4451310).

19814151813481 is an frugal number, since it uses more digits than its factorization.

19814151813481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8902618 (or 4451309 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 55.

The spelling of 19814151813481 in words is "nineteen trillion, eight hundred fourteen billion, one hundred fifty-one million, eight hundred thirteen thousand, four hundred eighty-one".