1287405 has 48 divisors (see below), whose sum is σ = 2630784. Its totient is φ = 570240.

The previous prime is 1287401. The next prime is 1287431. The reversal of 1287405 is 5047821.

1287405 = 36² + 37² + ... + 157².

It is not a de Polignac number, because 1287405 - 2² = 1287401 is a prime.

It is a Curzon 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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19182 + ... + 19248.

It is an arithmetic number, because the mean of its divisors is an integer number (54808).

2^1287405 is an apocalyptic number.

1287405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1287405 is an abundant number, since it is smaller than the sum of its proper divisors (1343379).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287405 is a wasteful number, since it uses less digits than its factorization.

1287405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 1287405 is about 1134.6387090171. The cubic root of 1287405 is about 108.7856799294.

The spelling of 1287405 in words is "one million, two hundred eighty-seven thousand, four hundred five".