111421987 has 4 divisors (see below), whose sum is σ = 114013240. Its totient is φ = 108830736.

The previous prime is 111421957. The next prime is 111422009. The reversal of 111421987 is 789124111.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111421987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111421957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1295562 + ... + 1295647.

It is an arithmetic number, because the mean of its divisors is an integer number (28503310).

Almost surely, 2^111421987 is an apocalyptic number.

111421987 is a deficient number, since it is larger than the sum of its proper divisors (2591253).

111421987 is an equidigital number, since it uses as much as digits as its factorization.

111421987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591252.

The product of its digits is 4032, while the sum is 34.

The square root of 111421987 is about 10555.6613719842. The cubic root of 111421987 is about 481.1977998815.

The spelling of 111421987 in words is "one hundred eleven million, four hundred twenty-one thousand, nine hundred eighty-seven".