1267840 has 64 divisors (see below), whose sum is σ = 3476160. Its totient is φ = 433152.

The previous prime is 1267837. The next prime is 1267859. The reversal of 1267840 is 487621.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1267799 and 1267808.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4339 + ... + 4621.

It is an arithmetic number, because the mean of its divisors is an integer number (54315).

2^1267840 is an apocalyptic number.

1267840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1267840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1738080).

1267840 is an abundant number, since it is smaller than the sum of its proper divisors (2208320).

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

1267840 is an equidigital number, since it uses as much as digits as its factorization.

1267840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 1267840 is about 1125.9840140961. The cubic root of 1267840 is about 108.2317838663.

The spelling of 1267840 in words is "one million, two hundred sixty-seven thousand, eight hundred forty".