123415312721 has 2 divisors, whose sum is σ = 123415312722. Its totient is φ = 123415312720.

The previous prime is 123415312663. The next prime is 123415312753. The reversal of 123415312721 is 127213514321.

It is an a-pointer prime, because the next prime (123415312753) can be obtained adding 123415312721 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70405315600 + 53009997121 = 265340^2 + 230239^2 .

It is a cyclic number.

It is not a de Polignac number, because 123415312721 - 2¹⁴ = 123415296337 is a prime.

It is not a weakly prime, because it can be changed into another prime (123415317721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61707656360 + 61707656361.

It is an arithmetic number, because the mean of its divisors is an integer number (61707656361).

Almost surely, 2^123415312721 is an apocalyptic number.

It is an amenable number.

123415312721 is a deficient number, since it is larger than the sum of its proper divisors (1).

123415312721 is an equidigital number, since it uses as much as digits as its factorization.

123415312721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 32.

The spelling of 123415312721 in words is "one hundred twenty-three billion, four hundred fifteen million, three hundred twelve thousand, seven hundred twenty-one".