85581001 has 15 divisors (see below), whose sum is σ = 97427953. Its totient is φ = 75118120.

The previous prime is 85580993. The next prime is 85581007. The reversal of 85581001 is 10018558.

The square root of 85581001 is 9251.

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

It can be written as a sum of positive squares in 2 ways, for example, as 203401 + 85377600 = 451^2 + 9240^2 .

It is not a de Polignac number, because 85581001 - 2³ = 85580993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85581007) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2951055 + ... + 2951083.

Almost surely, 2^85581001 is an apocalyptic number.

85581001 is the 9251-st square number.

85581001 is the 4626-th centered octagonal number.

It is an amenable number.

85581001 is a deficient number, since it is larger than the sum of its proper divisors (11846952).

85581001 is an frugal number, since it uses more digits than its factorization.

85581001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 28.

The cubic root of 85581001 is about 440.6824825230.

Multiplying 85581001 by its product of nonzero digits (1600), we get a square (136929601600 = 370040²).

Adding to 85581001 its reverse (10018558), we get a palindrome (95599559).

It can be divided in two parts, 8558 and 1001, that added together give a palindrome (9559).

The spelling of 85581001 in words is "eighty-five million, five hundred eighty-one thousand, one".