1987281 has 16 divisors (see below), whose sum is σ = 2980800. Its totient is φ = 1308384.

The previous prime is 1987277. The next prime is 1987291. The reversal of 1987281 is 1827891.

It is not a de Polignac number, because 1987281 - 2² = 1987277 is a prime.

It is a super-2 number, since 2×1987281² = 7898571545922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1987201) 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 15 ways as a sum of consecutive naturals, for example, 1990 + ... + 2816.

It is an arithmetic number, because the mean of its divisors is an integer number (186300).

2^1987281 is an apocalyptic number.

It is an amenable number.

1987281 is a deficient number, since it is larger than the sum of its proper divisors (993519).

1987281 is an equidigital number, since it uses as much as digits as its factorization.

1987281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925 (or 919 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 1987281 is about 1409.7095445516. The cubic root of 1987281 is about 125.7244545469.

The spelling of 1987281 in words is "one million, nine hundred eighty-seven thousand, two hundred eighty-one".