1261987 has 4 divisors (see below), whose sum is σ = 1316880. Its totient is φ = 1207096.

The previous prime is 1261973. The next prime is 1262011. The reversal of 1261987 is 7891621.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7891621 = 17 ⋅464213.

It is a cyclic number.

It is not a de Polignac number, because 1261987 - 2¹¹ = 1259939 is a prime.

It is a super-2 number, since 2×1261987² = 3185222376338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27412 + ... + 27457.

It is an arithmetic number, because the mean of its divisors is an integer number (329220).

2^1261987 is an apocalyptic number.

1261987 is a deficient number, since it is larger than the sum of its proper divisors (54893).

1261987 is an equidigital number, since it uses as much as digits as its factorization.

1261987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54892.

The product of its digits is 6048, while the sum is 34.

The square root of 1261987 is about 1123.3819475138. The cubic root of 1261987 is about 108.0649757615.

The spelling of 1261987 in words is "one million, two hundred sixty-one thousand, nine hundred eighty-seven".