123400420081 has 2 divisors, whose sum is σ = 123400420082. Its totient is φ = 123400420080.

The previous prime is 123400420061. The next prime is 123400420139. The reversal of 123400420081 is 180024004321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119031210081 + 4369210000 = 345009^2 + 66100^2 .

It is a cyclic number.

It is not a de Polignac number, because 123400420081 - 2¹⁹ = 123399895793 is a prime.

It is a super-2 number, since 2×123400420081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (123400420001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61700210040 + 61700210041.

It is an arithmetic number, because the mean of its divisors is an integer number (61700210041).

Almost surely, 2^123400420081 is an apocalyptic number.

It is an amenable number.

123400420081 is a deficient number, since it is larger than the sum of its proper divisors (1).

123400420081 is an equidigital number, since it uses as much as digits as its factorization.

123400420081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 25.

The spelling of 123400420081 in words is "one hundred twenty-three billion, four hundred million, four hundred twenty thousand, eighty-one".