71780532561 has 8 divisors (see below), whose sum is σ = 106341529760. Its totient is φ = 47853688356.

The previous prime is 71780532559. The next prime is 71780532587. The reversal of 71780532561 is 16523508717.

It is a happy number.

71780532561 is a `hidden beast` number, since 7 + 1 + 7 + 80 + 5 + 3 + 2 + 561 = 666.

It is not a de Polignac number, because 71780532561 - 2¹ = 71780532559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71780532521) 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, 1329269095 + ... + 1329269148.

It is an arithmetic number, because the mean of its divisors is an integer number (13292691220).

Almost surely, 2^71780532561 is an apocalyptic number.

It is an amenable number.

71780532561 is a deficient number, since it is larger than the sum of its proper divisors (34560997199).

71780532561 is a wasteful number, since it uses less digits than its factorization.

71780532561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2658538252 (or 2658538246 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 45.

The spelling of 71780532561 in words is "seventy-one billion, seven hundred eighty million, five hundred thirty-two thousand, five hundred sixty-one".