1291028 has 6 divisors (see below), whose sum is σ = 2259306. Its totient is φ = 645512.

The previous prime is 1291021. The next prime is 1291063. The reversal of 1291028 is 8201921.

It can be written as a sum of positive squares in only one way, i.e., 1281424 + 9604 = 1132^2 + 98^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1290994 and 1291012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161375 + ... + 161382.

It is an arithmetic number, because the mean of its divisors is an integer number (376551).

2^1291028 is an apocalyptic number.

It is an amenable number.

1291028 is a deficient number, since it is larger than the sum of its proper divisors (968278).

1291028 is a wasteful number, since it uses less digits than its factorization.

1291028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322761 (or 322759 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1291028 is about 1136.2341308023. The cubic root of 1291028 is about 108.8876321449.

Adding to 1291028 its reverse (8201921), we get a palindrome (9492949).

The spelling of 1291028 in words is "one million, two hundred ninety-one thousand, twenty-eight".