1291947372 has 18 divisors (see below), whose sum is σ = 3265755948. Its totient is φ = 430649112.

The previous prime is 1291947353. The next prime is 1291947383. The reversal of 1291947372 is 2737491921.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17943678 + ... + 17943749.

It is an arithmetic number, because the mean of its divisors is an integer number (181430886).

Almost surely, 2^1291947372 is an apocalyptic number.

1291947372 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1291947372 is an abundant number, since it is smaller than the sum of its proper divisors (1973808576).

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

1291947372 is a wasteful number, since it uses less digits than its factorization.

1291947372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35887437 (or 35887432 counting only the distinct ones).

The product of its digits is 190512, while the sum is 45.

The square root of 1291947372 is about 35943.6694287047. The cubic root of 1291947372 is about 1089.1347317662.

The spelling of 1291947372 in words is "one billion, two hundred ninety-one million, nine hundred forty-seven thousand, three hundred seventy-two".