1291240 has 32 divisors (see below), whose sum is σ = 3060000. Its totient is φ = 489024.

The previous prime is 1291229. The next prime is 1291249. The reversal of 1291240 is 421921.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (1291249) 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, 90 + ... + 1609.

It is an arithmetic number, because the mean of its divisors is an integer number (95625).

2^1291240 is an apocalyptic number.

1291240 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 1291240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1530000).

1291240 is an abundant number, since it is smaller than the sum of its proper divisors (1768760).

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

1291240 is a wasteful number, since it uses less digits than its factorization.

1291240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1729 (or 1725 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 1291240 is about 1136.3274176046. The cubic root of 1291240 is about 108.8935919730.

It can be divided in two parts, 129 and 1240, that added together give a square (1369 = 37²).

The spelling of 1291240 in words is "one million, two hundred ninety-one thousand, two hundred forty".