1989131 has 2 divisors, whose sum is σ = 1989132. Its totient is φ = 1989130.

The previous prime is 1989107. The next prime is 1989133. The reversal of 1989131 is 1319891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1989131 is a prime.

It is a super-2 number, since 2×1989131² = 7913284270322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1989133, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1989133) 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 as a sum of consecutive naturals, namely, 994565 + 994566.

It is an arithmetic number, because the mean of its divisors is an integer number (994566).

2^1989131 is an apocalyptic number.

1989131 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989131 is an equidigital number, since it uses as much as digits as its factorization.

1989131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 32.

The square root of 1989131 is about 1410.3655554501. The cubic root of 1989131 is about 125.7634555913.

The spelling of 1989131 in words is "one million, nine hundred eighty-nine thousand, one hundred thirty-one".