1291977919885 has 8 divisors (see below), whose sum is σ = 1550390460696. Its totient is φ = 1033571031360.

The previous prime is 1291977919879. The next prime is 1291977919927. The reversal of 1291977919885 is 5889197791921.

It can be written as a sum of positive squares in 4 ways, for example, as 257904512649 + 1034073407236 = 507843^2 + 1016894^2 .

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

It is not a de Polignac number, because 1291977919885 - 2¹⁷ = 1291977788813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 892786 + ... + 1838755.

It is an arithmetic number, because the mean of its divisors is an integer number (193798807587).

Almost surely, 2^{1291977919885} is an apocalyptic number.

It is an amenable number.

1291977919885 is a deficient number, since it is larger than the sum of its proper divisors (258412540811).

1291977919885 is an equidigital number, since it uses as much as digits as its factorization.

1291977919885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2826143.

The product of its digits is 205752960, while the sum is 76.

The spelling of 1291977919885 in words is "one trillion, two hundred ninety-one billion, nine hundred seventy-seven million, nine hundred nineteen thousand, eight hundred eighty-five".