1287898 has 4 divisors (see below), whose sum is σ = 1931850. Its totient is φ = 643948.

The previous prime is 1287887. The next prime is 1287899. The reversal of 1287898 is 8987821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8987821 = 83 ⋅108287.

It can be written as a sum of positive squares in only one way, i.e., 1216609 + 71289 = 1103^2 + 267^2 .

It is not an unprimeable number, because it can be changed into a prime (1287899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321973 + ... + 321976.

2^1287898 is an apocalyptic number.

1287898 is a deficient number, since it is larger than the sum of its proper divisors (643952).

1287898 is an equidigital number, since it uses as much as digits as its factorization.

1287898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643951.

The product of its digits is 64512, while the sum is 43.

The square root of 1287898 is about 1134.8559379939. The cubic root of 1287898 is about 108.7995643185.

The spelling of 1287898 in words is "one million, two hundred eighty-seven thousand, eight hundred ninety-eight".