1291388 has 24 divisors (see below), whose sum is σ = 2735712. Its totient is φ = 520704.

The previous prime is 1291387. The next prime is 1291391. The reversal of 1291388 is 8831921.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291387) 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, 881 + ... + 1832.

It is an arithmetic number, because the mean of its divisors is an integer number (113988).

2^1291388 is an apocalyptic number.

It is an amenable number.

1291388 is an abundant number, since it is smaller than the sum of its proper divisors (1444324).

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

1291388 is a wasteful number, since it uses less digits than its factorization.

1291388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2741 (or 2739 counting only the distinct ones).

The product of its digits is 3456, while the sum is 32.

The square root of 1291388 is about 1136.3925378143. The cubic root of 1291388 is about 108.8977522210.

The spelling of 1291388 in words is "one million, two hundred ninety-one thousand, three hundred eighty-eight".