13381551 has 8 divisors (see below), whose sum is σ = 19824560. Its totient is φ = 8921016.

The previous prime is 13381549. The next prime is 13381597. The reversal of 13381551 is 15518331.

13381551 is a `hidden beast` number, since 1 + 33 + 81 + 551 = 666.

It is not a de Polignac number, because 13381551 - 2¹ = 13381549 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 495613 = 13381551 / (1 + 3 + 3 + 8 + 1 + 5 + 5 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13381751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 247780 + ... + 247833.

It is an arithmetic number, because the mean of its divisors is an integer number (2478070).

Almost surely, 2^13381551 is an apocalyptic number.

13381551 is a deficient number, since it is larger than the sum of its proper divisors (6443009).

13381551 is an equidigital number, since it uses as much as digits as its factorization.

13381551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495622 (or 495616 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 13381551 is about 3658.0802342212. The cubic root of 13381551 is about 237.4117182505.

Adding to 13381551 its reverse (15518331), we get a palindrome (28899882).

The spelling of 13381551 in words is "thirteen million, three hundred eighty-one thousand, five hundred fifty-one".