381111989 has 2 divisors, whose sum is σ = 381111990. Its totient is φ = 381111988.

The previous prime is 381111979. The next prime is 381112009. The reversal of 381111989 is 989111183.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 376942225 + 4169764 = 19415^2 + 2042^2 .

It is a cyclic number.

It is not a de Polignac number, because 381111989 - 2¹⁶ = 381046453 is a prime.

It is a super-2 number, since 2×381111989² = 290492696319072242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381111919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190555994 + 190555995.

It is an arithmetic number, because the mean of its divisors is an integer number (190555995).

Almost surely, 2^381111989 is an apocalyptic number.

It is an amenable number.

381111989 is a deficient number, since it is larger than the sum of its proper divisors (1).

381111989 is an equidigital number, since it uses as much as digits as its factorization.

381111989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 41.

The square root of 381111989 is about 19522.0897703089. The cubic root of 381111989 is about 725.0214747503.

The spelling of 381111989 in words is "three hundred eighty-one million, one hundred eleven thousand, nine hundred eighty-nine".