4085638561 has 9 divisors (see below), whose sum is σ = 4190406643. Its totient is φ = 3983432080.

The previous prime is 4085638489. The next prime is 4085638573. The reversal of 4085638561 is 1658365804.

The square root of 4085638561 is 63919.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 196868961 + 3888769600 = 14031^2 + 62360^2 .

It is not a de Polignac number, because 4085638561 - 2¹⁵ = 4085605793 is a prime.

It is a super-2 number, since 2×4085638561² = 33384884902260301442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4085638061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2619900 + ... + 2621458.

Almost surely, 2^4085638561 is an apocalyptic number.

4085638561 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

4085638561 is the 63919-th square number.

4085638561 is the 31960-th centered octagonal number.

It is an amenable number.

4085638561 is a deficient number, since it is larger than the sum of its proper divisors (104768082).

4085638561 is an frugal number, since it uses more digits than its factorization.

4085638561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3200 (or 1600 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 46.

The cubic root of 4085638561 is about 1598.6497150741.

The spelling of 4085638561 in words is "four billion, eighty-five million, six hundred thirty-eight thousand, five hundred sixty-one".