1291823988 has 48 divisors (see below), whose sum is σ = 3709856640. Its totient is φ = 340700544.

The previous prime is 1291823983. The next prime is 1291823989. The reversal of 1291823988 is 8893281921.

It is a self number, because there is not a number n which added to its sum of digits gives 1291823988.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291823983) 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, 590403 + ... + 592586.

It is an arithmetic number, because the mean of its divisors is an integer number (77288680).

Almost surely, 2^1291823988 is an apocalyptic number.

It is an amenable number.

1291823988 is an abundant number, since it is smaller than the sum of its proper divisors (2418032652).

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

1291823988 is a wasteful number, since it uses less digits than its factorization.

1291823988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1183016 (or 1183014 counting only the distinct ones).

The product of its digits is 497664, while the sum is 51.

The square root of 1291823988 is about 35941.9530354153. The cubic root of 1291823988 is about 1089.1000590232.

The spelling of 1291823988 in words is "one billion, two hundred ninety-one million, eight hundred twenty-three thousand, nine hundred eighty-eight".