1287421 has 4 divisors (see below), whose sum is σ = 1355200. Its totient is φ = 1219644.

The previous prime is 1287401. The next prime is 1287431. The reversal of 1287421 is 1247821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1247821 = 229 ⋅5449.

It is a cyclic number.

It is not a de Polignac number, because 1287421 - 2¹⁵ = 1254653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33861 + ... + 33898.

It is an arithmetic number, because the mean of its divisors is an integer number (338800).

2^1287421 is an apocalyptic number.

It is an amenable number.

1287421 is a deficient number, since it is larger than the sum of its proper divisors (67779).

1287421 is an equidigital number, since it uses as much as digits as its factorization.

1287421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67778.

The product of its digits is 896, while the sum is 25.

The square root of 1287421 is about 1134.6457596977. The cubic root of 1287421 is about 108.7861305940.

The spelling of 1287421 in words is "one million, two hundred eighty-seven thousand, four hundred twenty-one".