1281918 has 16 divisors (see below), whose sum is σ = 2797056. Its totient is φ = 388440.

The previous prime is 1281899. The next prime is 1281937. The reversal of 1281918 is 8191821.

It is an interprime number because it is at equal distance from previous prime (1281899) and next prime (1281937).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9646 + ... + 9777.

It is an arithmetic number, because the mean of its divisors is an integer number (174816).

2^1281918 is an apocalyptic number.

1281918 is an abundant number, since it is smaller than the sum of its proper divisors (1515138).

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

1281918 is a wasteful number, since it uses less digits than its factorization.

1281918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19439.

The product of its digits is 1152, while the sum is 30.

The square root of 1281918 is about 1132.2181768546. The cubic root of 1281918 is about 108.6309094006.

Subtracting 1281918 from its reverse (8191821), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 1281918 in words is "one million, two hundred eighty-one thousand, nine hundred eighteen".