123240325981 has 2 divisors, whose sum is σ = 123240325982. Its totient is φ = 123240325980.

The previous prime is 123240325979. The next prime is 123240325991. The reversal of 123240325981 is 189523042321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91043406756 + 32196919225 = 301734^2 + 179435^2 .

It is an emirp because it is prime and its reverse (189523042321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123240325981 - 2¹ = 123240325979 is a prime.

It is a super-2 number, since 2×123240325981² (a number of 23 digits) contains 22 as substring.

Together with 123240325979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123240325921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61620162990 + 61620162991.

It is an arithmetic number, because the mean of its divisors is an integer number (61620162991).

Almost surely, 2^123240325981 is an apocalyptic number.

It is an amenable number.

123240325981 is a deficient number, since it is larger than the sum of its proper divisors (1).

123240325981 is an equidigital number, since it uses as much as digits as its factorization.

123240325981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 123240325981 in words is "one hundred twenty-three billion, two hundred forty million, three hundred twenty-five thousand, nine hundred eighty-one".