1291293828 has 72 divisors (see below), whose sum is σ = 3580930080. Its totient is φ = 389093760.

The previous prime is 1291293797. The next prime is 1291293833. The reversal of 1291293828 is 8283921921.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61776 + ... + 79992.

It is an arithmetic number, because the mean of its divisors is an integer number (49735140).

Almost surely, 2^1291293828 is an apocalyptic number.

1291293828 is a gapful number since it is divisible by the number (18) 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 1291293828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1790465040).

1291293828 is an abundant number, since it is smaller than the sum of its proper divisors (2289636252).

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

1291293828 is a wasteful number, since it uses less digits than its factorization.

1291293828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18417 (or 18412 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 1291293828 is about 35934.5770533062. The cubic root of 1291293828 is about 1088.9510510319.

The spelling of 1291293828 in words is "one billion, two hundred ninety-one million, two hundred ninety-three thousand, eight hundred twenty-eight".