71561780057123 has 2 divisors, whose sum is σ = 71561780057124. Its totient is φ = 71561780057122.

The previous prime is 71561780056973. The next prime is 71561780057147. The reversal of 71561780057123 is 32175008716517.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 71561780057123 - 2⁸ = 71561780056867 is a prime.

It is a super-2 number, since 2×71561780057123² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (71561780051123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35780890028561 + 35780890028562.

It is an arithmetic number, because the mean of its divisors is an integer number (35780890028562).

Almost surely, 2^{71561780057123} is an apocalyptic number.

71561780057123 is a deficient number, since it is larger than the sum of its proper divisors (1).

71561780057123 is an equidigital number, since it uses as much as digits as its factorization.

71561780057123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2469600, while the sum is 53.

The spelling of 71561780057123 in words is "seventy-one trillion, five hundred sixty-one billion, seven hundred eighty million, fifty-seven thousand, one hundred twenty-three".