1249205705123 has 2 divisors, whose sum is σ = 1249205705124. Its totient is φ = 1249205705122.

The previous prime is 1249205705021. The next prime is 1249205705131. The reversal of 1249205705123 is 3215075029421.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (3215075029421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1249205705123 - 2²² = 1249201510819 is a prime.

It is not a weakly prime, because it can be changed into another prime (1249205705173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624602852561 + 624602852562.

It is an arithmetic number, because the mean of its divisors is an integer number (624602852562).

Almost surely, 2^{1249205705123} is an apocalyptic number.

1249205705123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249205705123 is an equidigital number, since it uses as much as digits as its factorization.

1249205705123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 1249205705123 in words is "one trillion, two hundred forty-nine billion, two hundred five million, seven hundred five thousand, one hundred twenty-three".