71521508977 has 2 divisors, whose sum is σ = 71521508978. Its totient is φ = 71521508976.

The previous prime is 71521508953. The next prime is 71521509011. The reversal of 71521508977 is 77980512517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39993600256 + 31527908721 = 199984^2 + 177561^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71521508977 is a prime.

It is not a weakly prime, because it can be changed into another prime (71521508077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35760754488 + 35760754489.

It is an arithmetic number, because the mean of its divisors is an integer number (35760754489).

Almost surely, 2^71521508977 is an apocalyptic number.

It is an amenable number.

71521508977 is a deficient number, since it is larger than the sum of its proper divisors (1).

71521508977 is an equidigital number, since it uses as much as digits as its factorization.

71521508977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1234800, while the sum is 52.

The spelling of 71521508977 in words is "seventy-one billion, five hundred twenty-one million, five hundred eight thousand, nine hundred seventy-seven".