1281987 has 60 divisors (see below), whose sum is σ = 2482920. Its totient is φ = 653184.

The previous prime is 1281983. The next prime is 1282007. The reversal of 1281987 is 7891821.

It is not a de Polignac number, because 1281987 - 2² = 1281983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281983) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 67464 + ... + 67482.

It is an arithmetic number, because the mean of its divisors is an integer number (41382).

2^1281987 is an apocalyptic number.

1281987 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1281987 is a deficient number, since it is larger than the sum of its proper divisors (1200933).

1281987 is a wasteful number, since it uses less digits than its factorization.

1281987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62 (or 46 counting only the distinct ones).

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

The square root of 1281987 is about 1132.2486476035. The cubic root of 1281987 is about 108.6328584068.

The spelling of 1281987 in words is "one million, two hundred eighty-one thousand, nine hundred eighty-seven".