124206720721 has 2 divisors, whose sum is σ = 124206720722. Its totient is φ = 124206720720.

The previous prime is 124206720719. The next prime is 124206720863. The reversal of 124206720721 is 127027602421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102262446225 + 21944274496 = 319785^2 + 148136^2 .

It is a cyclic number.

It is not a de Polignac number, because 124206720721 - 2¹ = 124206720719 is a prime.

Together with 124206720719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (124206723721) 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, 62103360360 + 62103360361.

It is an arithmetic number, because the mean of its divisors is an integer number (62103360361).

Almost surely, 2^124206720721 is an apocalyptic number.

It is an amenable number.

124206720721 is a deficient number, since it is larger than the sum of its proper divisors (1).

124206720721 is an equidigital number, since it uses as much as digits as its factorization.

124206720721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 34.

The spelling of 124206720721 in words is "one hundred twenty-four billion, two hundred six million, seven hundred twenty thousand, seven hundred twenty-one".