12054991981 has 2 divisors, whose sum is σ = 12054991982. Its totient is φ = 12054991980.

The previous prime is 12054991967. The next prime is 12054992011. The reversal of 12054991981 is 18919945021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11866616356 + 188375625 = 108934^2 + 13725^2 .

It is a cyclic number.

It is not a de Polignac number, because 12054991981 - 2²⁷ = 11920774253 is a prime.

It is a super-2 number, since 2×12054991981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12054992981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6027495990 + 6027495991.

It is an arithmetic number, because the mean of its divisors is an integer number (6027495991).

Almost surely, 2^12054991981 is an apocalyptic number.

It is an amenable number.

12054991981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12054991981 is an equidigital number, since it uses as much as digits as its factorization.

12054991981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 49.

The spelling of 12054991981 in words is "twelve billion, fifty-four million, nine hundred ninety-one thousand, nine hundred eighty-one".