1291859123 has 2 divisors, whose sum is σ = 1291859124. Its totient is φ = 1291859122.

The previous prime is 1291859071. The next prime is 1291859137. The reversal of 1291859123 is 3219581921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1291859123 - 2¹² = 1291855027 is a prime.

It is not a weakly prime, because it can be changed into another prime (1291859183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645929561 + 645929562.

It is an arithmetic number, because the mean of its divisors is an integer number (645929562).

Almost surely, 2^1291859123 is an apocalyptic number.

1291859123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291859123 is an equidigital number, since it uses as much as digits as its factorization.

1291859123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 41.

The square root of 1291859123 is about 35942.4418063103. The cubic root of 1291859123 is about 1089.1099327067.

The spelling of 1291859123 in words is "one billion, two hundred ninety-one million, eight hundred fifty-nine thousand, one hundred twenty-three".