11981991427415 has 4 divisors (see below), whose sum is σ = 14378389712904. Its totient is φ = 9585593141928.

The previous prime is 11981991427337. The next prime is 11981991427541. The reversal of 11981991427415 is 51472419918911.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11981991427415 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 3 ways as a sum of consecutive naturals, for example, 1198199142737 + ... + 1198199142746.

It is an arithmetic number, because the mean of its divisors is an integer number (3594597428226).

Almost surely, 2^{11981991427415} is an apocalyptic number.

11981991427415 is a deficient number, since it is larger than the sum of its proper divisors (2396398285489).

11981991427415 is an equidigital number, since it uses as much as digits as its factorization.

11981991427415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2396398285488.

The product of its digits is 6531840, while the sum is 62.

The spelling of 11981991427415 in words is "eleven trillion, nine hundred eighty-one billion, nine hundred ninety-one million, four hundred twenty-seven thousand, four hundred fifteen".