111531401 has 2 divisors, whose sum is σ = 111531402. Its totient is φ = 111531400.

The previous prime is 111531377. The next prime is 111531403. The reversal of 111531401 is 104135111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111281401 + 250000 = 10549^2 + 500^2 .

It is a cyclic number.

It is not a de Polignac number, because 111531401 - 2⁶ = 111531337 is a prime.

It is a Sophie Germain prime.

Together with 111531403, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 111531401.

It is not a weakly prime, because it can be changed into another prime (111531403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55765700 + 55765701.

It is an arithmetic number, because the mean of its divisors is an integer number (55765701).

Almost surely, 2^111531401 is an apocalyptic number.

It is an amenable number.

111531401 is a deficient number, since it is larger than the sum of its proper divisors (1).

111531401 is an equidigital number, since it uses as much as digits as its factorization.

111531401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 111531401 is about 10560.8428167453. The cubic root of 111531401 is about 481.3552569904.

Adding to 111531401 its reverse (104135111), we get a palindrome (215666512).

The spelling of 111531401 in words is "one hundred eleven million, five hundred thirty-one thousand, four hundred one".