1291356 has 48 divisors (see below), whose sum is σ = 3655680. Its totient is φ = 390960.

The previous prime is 1291349. The next prime is 1291357. The reversal of 1291356 is 6531921.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 645 + ... + 1731.

It is an arithmetic number, because the mean of its divisors is an integer number (76160).

2^1291356 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1291356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1827840).

1291356 is an abundant number, since it is smaller than the sum of its proper divisors (2364324).

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

1291356 is a wasteful number, since it uses less digits than its factorization.

1291356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111 (or 1103 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 1291356 is about 1136.3784580852. The cubic root of 1291356 is about 108.8968527348.

It can be divided in two parts, 129 and 1356, that added together give a triangular number (1485 = T₅₄).

The spelling of 1291356 in words is "one million, two hundred ninety-one thousand, three hundred fifty-six".