11997461881 has 2 divisors, whose sum is σ = 11997461882. Its totient is φ = 11997461880.

The previous prime is 11997461873. The next prime is 11997461893. The reversal of 11997461881 is 18816479911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7865029225 + 4132432656 = 88685^2 + 64284^2 .

It is an emirp because it is prime and its reverse (18816479911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11997461881 - 2³ = 11997461873 is a prime.

It is a super-2 number, since 2×11997461881² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11997461831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5998730940 + 5998730941.

It is an arithmetic number, because the mean of its divisors is an integer number (5998730941).

Almost surely, 2^11997461881 is an apocalyptic number.

It is an amenable number.

11997461881 is a deficient number, since it is larger than the sum of its proper divisors (1).

11997461881 is an equidigital number, since it uses as much as digits as its factorization.

11997461881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 55.

The spelling of 11997461881 in words is "eleven billion, nine hundred ninety-seven million, four hundred sixty-one thousand, eight hundred eighty-one".