1291520 has 36 divisors (see below), whose sum is σ = 3096660. Its totient is φ = 516096.

The previous prime is 1291501. The next prime is 1291523. The reversal of 1291520 is 251921.

It can be written as a sum of positive squares in 2 ways, for example, as 430336 + 861184 = 656^2 + 928^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1291492 and 1291501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 776 + ... + 1784.

2^1291520 is an apocalyptic number.

1291520 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 1291520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1548330).

1291520 is an abundant number, since it is smaller than the sum of its proper divisors (1805140).

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

1291520 is an equidigital number, since it uses as much as digits as its factorization.

1291520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030 (or 1016 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 1291520 is about 1136.4506148531. The cubic root of 1291520 is about 108.9014624443.

The spelling of 1291520 in words is "one million, two hundred ninety-one thousand, five hundred twenty".