71657676821557 has 2 divisors, whose sum is σ = 71657676821558. Its totient is φ = 71657676821556.

The previous prime is 71657676821483. The next prime is 71657676821651. The reversal of 71657676821557 is 75512867675617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57572675327556 + 14085001494001 = 7587666^2 + 3752999^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71657676821557 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71657676821557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71657676021557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35828838410778 + 35828838410779.

It is an arithmetic number, because the mean of its divisors is an integer number (35828838410779).

Almost surely, 2^{71657676821557} is an apocalyptic number.

It is an amenable number.

71657676821557 is a deficient number, since it is larger than the sum of its proper divisors (1).

71657676821557 is an equidigital number, since it uses as much as digits as its factorization.

71657676821557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1037232000, while the sum is 73.

The spelling of 71657676821557 in words is "seventy-one trillion, six hundred fifty-seven billion, six hundred seventy-six million, eight hundred twenty-one thousand, five hundred fifty-seven".