1291856364021 has 8 divisors (see below), whose sum is σ = 1725341169664. Its totient is φ = 859804567200.

The previous prime is 1291856364013. The next prime is 1291856364031. The reversal of 1291856364021 is 1204636581921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1291856364021 - 2³ = 1291856364013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291856364031) 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, 358250101 + ... + 358253706.

It is an arithmetic number, because the mean of its divisors is an integer number (215667646208).

Almost surely, 2^{1291856364021} is an apocalyptic number.

It is an amenable number.

1291856364021 is a deficient number, since it is larger than the sum of its proper divisors (433484805643).

1291856364021 is an equidigital number, since it uses as much as digits as its factorization.

1291856364021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716504411.

The product of its (nonzero) digits is 622080, while the sum is 48.

The spelling of 1291856364021 in words is "one trillion, two hundred ninety-one billion, eight hundred fifty-six million, three hundred sixty-four thousand, twenty-one".