71662600721 has 2 divisors, whose sum is σ = 71662600722. Its totient is φ = 71662600720.

The previous prime is 71662600693. The next prime is 71662600783. The reversal of 71662600721 is 12700626617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45665553025 + 25997047696 = 213695^2 + 161236^2 .

It is a cyclic number.

It is not a de Polignac number, because 71662600721 - 2⁶ = 71662600657 is a prime.

It is a super-3 number, since 3×71662600721³ (a number of 34 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (71662600021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35831300360 + 35831300361.

It is an arithmetic number, because the mean of its divisors is an integer number (35831300361).

Almost surely, 2^71662600721 is an apocalyptic number.

It is an amenable number.

71662600721 is a deficient number, since it is larger than the sum of its proper divisors (1).

71662600721 is an equidigital number, since it uses as much as digits as its factorization.

71662600721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42336, while the sum is 38.

The spelling of 71662600721 in words is "seventy-one billion, six hundred sixty-two million, six hundred thousand, seven hundred twenty-one".