111539381 has 2 divisors, whose sum is σ = 111539382. Its totient is φ = 111539380.

The previous prime is 111539371. The next prime is 111539383. The reversal of 111539381 is 183935111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 109537156 + 2002225 = 10466^2 + 1415^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111539381 is a prime.

It is a super-2 number, since 2×111539381² = 24882067027726322, which contains 22 as substring.

Together with 111539383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111539383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55769690 + 55769691.

It is an arithmetic number, because the mean of its divisors is an integer number (55769691).

Almost surely, 2^111539381 is an apocalyptic number.

It is an amenable number.

111539381 is a deficient number, since it is larger than the sum of its proper divisors (1).

111539381 is an equidigital number, since it uses as much as digits as its factorization.

111539381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 32.

The square root of 111539381 is about 10561.2206207427. The cubic root of 111539381 is about 481.3667369363.

The spelling of 111539381 in words is "one hundred eleven million, five hundred thirty-nine thousand, three hundred eighty-one".