1381186521 has 24 divisors (see below), whose sum is σ = 2343833856. Its totient is φ = 772691040.

The previous prime is 1381186511. The next prime is 1381186523. The reversal of 1381186521 is 1256811831.

1381186521 is a `hidden beast` number, since 13 + 8 + 118 + 6 + 521 = 666.

It is not a de Polignac number, because 1381186521 - 2¹⁰ = 1381185497 is a prime.

It is a super-3 number, since 3×1381186521³ (a number of 28 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1381186523) 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 23 ways as a sum of consecutive naturals, for example, 535305 + ... + 537878.

It is an arithmetic number, because the mean of its divisors is an integer number (97659744).

Almost surely, 2^1381186521 is an apocalyptic number.

1381186521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1381186521 is a deficient number, since it is larger than the sum of its proper divisors (962647335).

1381186521 is a wasteful number, since it uses less digits than its factorization.

1381186521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073213 (or 1073210 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 1381186521 is about 37164.3178465581. The cubic root of 1381186521 is about 1113.6552714876.

The spelling of 1381186521 in words is "one billion, three hundred eighty-one million, one hundred eighty-six thousand, five hundred twenty-one".