71745561 has 8 divisors (see below), whose sum is σ = 106289760. Its totient is φ = 47830356.

The previous prime is 71745551. The next prime is 71745581. The reversal of 71745561 is 16554717.

It is not a de Polignac number, because 71745561 - 2⁷ = 71745433 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (71745511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1328595 + ... + 1328648.

It is an arithmetic number, because the mean of its divisors is an integer number (13286220).

Almost surely, 2^71745561 is an apocalyptic number.

It is an amenable number.

71745561 is a deficient number, since it is larger than the sum of its proper divisors (34544199).

71745561 is a wasteful number, since it uses less digits than its factorization.

71745561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2657252 (or 2657246 counting only the distinct ones).

The product of its digits is 29400, while the sum is 36.

The square root of 71745561 is about 8470.2751431108. The cubic root of 71745561 is about 415.5261358007.

The spelling of 71745561 in words is "seventy-one million, seven hundred forty-five thousand, five hundred sixty-one".