11381391 has 24 divisors (see below), whose sum is σ = 19487104. Its totient is φ = 6502680.

The previous prime is 11381353. The next prime is 11381393. The reversal of 11381391 is 19318311.

It is a happy number.

It is not a de Polignac number, because 11381391 - 2⁶ = 11381327 is a prime.

It is a super-2 number, since 2×11381391² = 259072122189762, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11381393) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1645 + ... + 5046.

Almost surely, 2^11381391 is an apocalyptic number.

11381391 is a deficient number, since it is larger than the sum of its proper divisors (8105713).

11381391 is an frugal number, since it uses more digits than its factorization.

11381391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6713 (or 6701 counting only the distinct ones).

The product of its digits is 648, while the sum is 27.

The square root of 11381391 is about 3373.6317226396. The cubic root of 11381391 is about 224.9391835631.

The spelling of 11381391 in words is "eleven million, three hundred eighty-one thousand, three hundred ninety-one".