123517421 has 2 divisors, whose sum is σ = 123517422. Its totient is φ = 123517420.

The previous prime is 123517417. The next prime is 123517441. The reversal of 123517421 is 124715321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80102500 + 43414921 = 8950^2 + 6589^2 .

It is a cyclic number.

It is not a de Polignac number, because 123517421 - 2² = 123517417 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123517441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61758710 + 61758711.

It is an arithmetic number, because the mean of its divisors is an integer number (61758711).

Almost surely, 2^123517421 is an apocalyptic number.

It is an amenable number.

123517421 is a deficient number, since it is larger than the sum of its proper divisors (1).

123517421 is an equidigital number, since it uses as much as digits as its factorization.

123517421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 123517421 is about 11113.8391656529. The cubic root of 123517421 is about 498.0153608376.

The spelling of 123517421 in words is "one hundred twenty-three million, five hundred seventeen thousand, four hundred twenty-one".