123721428239 has 2 divisors, whose sum is σ = 123721428240. Its totient is φ = 123721428238.

The previous prime is 123721428209. The next prime is 123721428269. The reversal of 123721428239 is 932824127321.

It is a balanced prime because it is at equal distance from previous prime (123721428209) and next prime (123721428269).

It is an emirp because it is prime and its reverse (932824127321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123721428239 - 2¹² = 123721424143 is a prime.

It is a super-2 number, since 2×123721428239² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 123721428239.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123721428209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61860714119 + 61860714120.

It is an arithmetic number, because the mean of its divisors is an integer number (61860714120).

Almost surely, 2^123721428239 is an apocalyptic number.

123721428239 is a deficient number, since it is larger than the sum of its proper divisors (1).

123721428239 is an equidigital number, since it uses as much as digits as its factorization.

123721428239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 44.

The spelling of 123721428239 in words is "one hundred twenty-three billion, seven hundred twenty-one million, four hundred twenty-eight thousand, two hundred thirty-nine".