1988531 has 2 divisors, whose sum is σ = 1988532. Its totient is φ = 1988530.

The previous prime is 1988513. The next prime is 1988533. The reversal of 1988531 is 1358891.

Together with previous prime (1988513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (1358891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1988531 - 2¹⁴ = 1972147 is a prime.

It is a super-2 number, since 2×1988531² = 7908511075922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1988533, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1988491 and 1988500.

It is not a weakly prime, because it can be changed into another prime (1988533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994265 + 994266.

It is an arithmetic number, because the mean of its divisors is an integer number (994266).

2^1988531 is an apocalyptic number.

1988531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1988531 is an equidigital number, since it uses as much as digits as its factorization.

1988531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 35.

The square root of 1988531 is about 1410.1528285970. The cubic root of 1988531 is about 125.7508092545.

The spelling of 1988531 in words is "one million, nine hundred eighty-eight thousand, five hundred thirty-one".