1291473891623 has 2 divisors, whose sum is σ = 1291473891624. Its totient is φ = 1291473891622.

The previous prime is 1291473891613. The next prime is 1291473891637. The reversal of 1291473891623 is 3261983741921.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1291473891623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291473891613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645736945811 + 645736945812.

It is an arithmetic number, because the mean of its divisors is an integer number (645736945812).

Almost surely, 2^{1291473891623} is an apocalyptic number.

1291473891623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291473891623 is an equidigital number, since it uses as much as digits as its factorization.

1291473891623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3919104, while the sum is 56.

The spelling of 1291473891623 in words is "one trillion, two hundred ninety-one billion, four hundred seventy-three million, eight hundred ninety-one thousand, six hundred twenty-three".