1291249722 has 64 divisors (see below), whose sum is σ = 3130479360. Its totient is φ = 346622976.

The previous prime is 1291249703. The next prime is 1291249723. The reversal of 1291249722 is 2279421921.

It is not an unprimeable number, because it can be changed into a prime (1291249723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 539304 + ... + 541692.

It is an arithmetic number, because the mean of its divisors is an integer number (48913740).

Almost surely, 2^1291249722 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1291249722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1565239680).

1291249722 is an abundant number, since it is smaller than the sum of its proper divisors (1839229638).

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

1291249722 is a wasteful number, since it uses less digits than its factorization.

1291249722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3175.

The product of its digits is 36288, while the sum is 39.

The square root of 1291249722 is about 35933.9633494553. The cubic root of 1291249722 is about 1088.9386526604.

The spelling of 1291249722 in words is "one billion, two hundred ninety-one million, two hundred forty-nine thousand, seven hundred twenty-two".