85780561 has 4 divisors (see below), whose sum is σ = 86327092. Its totient is φ = 85234032.

The previous prime is 85780549. The next prime is 85780601. The reversal of 85780561 is 16508758.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12780625 + 72999936 = 3575^2 + 8544^2 .

It is a cyclic number.

It is not a de Polignac number, because 85780561 - 2⁷ = 85780433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85780511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273030 + ... + 273343.

It is an arithmetic number, because the mean of its divisors is an integer number (21581773).

Almost surely, 2^85780561 is an apocalyptic number.

It is an amenable number.

85780561 is a deficient number, since it is larger than the sum of its proper divisors (546531).

85780561 is a wasteful number, since it uses less digits than its factorization.

85780561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546530.

The product of its (nonzero) digits is 67200, while the sum is 40.

The square root of 85780561 is about 9261.7795806206. The cubic root of 85780561 is about 441.0247482439.

It can be divided in two parts, 857 and 80561, that added together give a palindrome (81418).

The spelling of 85780561 in words is "eighty-five million, seven hundred eighty thousand, five hundred sixty-one".