123519857556457 has 2 divisors, whose sum is σ = 123519857556458. Its totient is φ = 123519857556456.

The previous prime is 123519857556383. The next prime is 123519857556493. The reversal of 123519857556457 is 754655758915321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80119971352576 + 43399886203881 = 8950976^2 + 6587859^2 .

It is a cyclic number.

It is not a de Polignac number, because 123519857556457 - 2¹¹ = 123519857554409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123519857556457.

It is not a weakly prime, because it can be changed into another prime (123519857556497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61759928778228 + 61759928778229.

It is an arithmetic number, because the mean of its divisors is an integer number (61759928778229).

Almost surely, 2^{123519857556457} is an apocalyptic number.

It is an amenable number.

123519857556457 is a deficient number, since it is larger than the sum of its proper divisors (1).

123519857556457 is an equidigital number, since it uses as much as digits as its factorization.

123519857556457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1587600000, while the sum is 73.

The spelling of 123519857556457 in words is "one hundred twenty-three trillion, five hundred nineteen billion, eight hundred fifty-seven million, five hundred fifty-six thousand, four hundred fifty-seven".