1291179380 has 48 divisors (see below), whose sum is σ = 2852747856. Its totient is φ = 490245120.

The previous prime is 1291179349. The next prime is 1291179389. The reversal of 1291179380 is 839711921.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 58186384 + 1232992996 = 7628^2 + 35114^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291179389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9062 + ... + 51618.

It is an arithmetic number, because the mean of its divisors is an integer number (59432247).

Almost surely, 2^1291179380 is an apocalyptic number.

1291179380 is a gapful number since it is divisible by the number (10) 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 1291179380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426373928).

1291179380 is an abundant number, since it is smaller than the sum of its proper divisors (1561568476).

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

1291179380 is a wasteful number, since it uses less digits than its factorization.

1291179380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42644 (or 42642 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 1291179380 is about 35932.9845684992. The cubic root of 1291179380 is about 1088.9188786610.

The spelling of 1291179380 in words is "one billion, two hundred ninety-one million, one hundred seventy-nine thousand, three hundred eighty".