1291440768 has 64 divisors (see below), whose sum is σ = 3632195520. Its totient is φ = 405155840.

The previous prime is 1291440767. The next prime is 1291440781. The reversal of 1291440768 is 8670441921.

It is a tau number, because it is divible by the number of its divisors (64).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1291440763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92388 + ... + 105443.

It is an arithmetic number, because the mean of its divisors is an integer number (56753055).

Almost surely, 2^1291440768 is an apocalyptic number.

It is an amenable number.

1291440768 is an abundant number, since it is smaller than the sum of its proper divisors (2340754752).

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

1291440768 is a wasteful number, since it uses less digits than its factorization.

1291440768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197865 (or 197853 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 1291440768 is about 35936.6215440461. The cubic root of 1291440768 is about 1088.9923544118.

The spelling of 1291440768 in words is "one billion, two hundred ninety-one million, four hundred forty thousand, seven hundred sixty-eight".