71775561 has 16 divisors (see below), whose sum is σ = 112432320. Its totient is φ = 40153920.

The previous prime is 71775527. The next prime is 71775601. The reversal of 71775561 is 16557717.

It is not a de Polignac number, because 71775561 - 2¹⁰ = 71774537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (71775511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83226 + ... + 84083.

It is an arithmetic number, because the mean of its divisors is an integer number (7027020).

Almost surely, 2^71775561 is an apocalyptic number.

It is an amenable number.

71775561 is a deficient number, since it is larger than the sum of its proper divisors (40656759).

71775561 is a wasteful number, since it uses less digits than its factorization.

71775561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167336.

The product of its digits is 51450, while the sum is 39.

The square root of 71775561 is about 8472.0458568164. The cubic root of 71775561 is about 415.5840443636.

The spelling of 71775561 in words is "seventy-one million, seven hundred seventy-five thousand, five hundred sixty-one".