85561561 has 8 divisors (see below), whose sum is σ = 90987624. Its totient is φ = 80179200.

The previous prime is 85561523. The next prime is 85561577. The reversal of 85561561 is 16516558.

It can be written as a sum of positive squares in 4 ways, for example, as 28090000 + 57471561 = 5300^2 + 7581^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 85561561 - 2⁷ = 85561433 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 85561561.

It is not an unprimeable number, because it can be changed into a prime (85561061) 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, 6840 + ... + 14761.

It is an arithmetic number, because the mean of its divisors is an integer number (11373453).

Almost surely, 2^85561561 is an apocalyptic number.

It is an amenable number.

85561561 is a deficient number, since it is larger than the sum of its proper divisors (5426063).

85561561 is a wasteful number, since it uses less digits than its factorization.

85561561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21851.

The product of its digits is 36000, while the sum is 37.

The square root of 85561561 is about 9249.9492431040. The cubic root of 85561561 is about 440.6491125144.

The spelling of 85561561 in words is "eighty-five million, five hundred sixty-one thousand, five hundred sixty-one".