1281618 has 24 divisors (see below), whose sum is σ = 2990988. Its totient is φ = 394272.

The previous prime is 1281587. The next prime is 1281649. The reversal of 1281618 is 8161821.

It is an interprime number because it is at equal distance from previous prime (1281587) and next prime (1281649).

It can be written as a sum of positive squares in 2 ways, for example, as 1238769 + 42849 = 1113^2 + 207^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1281591 and 1281600.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2505 + ... + 2972.

2^1281618 is an apocalyptic number.

1281618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1281618 is an abundant number, since it is smaller than the sum of its proper divisors (1709370).

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

1281618 is a wasteful number, since it uses less digits than its factorization.

1281618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5498 (or 5495 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 1281618 is about 1132.0856858030. The cubic root of 1281618 is about 108.6224346476.

The spelling of 1281618 in words is "one million, two hundred eighty-one thousand, six hundred eighteen".