1287690 has 16 divisors (see below), whose sum is σ = 3090528. Its totient is φ = 343376.

The previous prime is 1287683. The next prime is 1287691. The reversal of 1287690 is 967821.

It is a super-2 number, since 2×1287690² = 3316291072200, which contains 22 as substring.

It is a nialpdrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (1287691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21432 + ... + 21491.

It is an arithmetic number, because the mean of its divisors is an integer number (193158).

2^1287690 is an apocalyptic number.

1287690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1287690 is an abundant number, since it is smaller than the sum of its proper divisors (1802838).

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

1287690 is a wasteful number, since it uses less digits than its factorization.

1287690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42933.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 1287690 is about 1134.7642927058. The cubic root of 1287690 is about 108.7937068340.

The spelling of 1287690 in words is "one million, two hundred eighty-seven thousand, six hundred ninety".