85661644 has 24 divisors (see below), whose sum is σ = 154018368. Its totient is φ = 41672400.

The previous prime is 85661603. The next prime is 85661651. The reversal of 85661644 is 44616658.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 85661597 and 85661606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20319 + ... + 24169.

It is an arithmetic number, because the mean of its divisors is an integer number (6417432).

Almost surely, 2^85661644 is an apocalyptic number.

It is an amenable number.

85661644 is a deficient number, since it is larger than the sum of its proper divisors (68356724).

85661644 is a wasteful number, since it uses less digits than its factorization.

85661644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4005 (or 4003 counting only the distinct ones).

The product of its digits is 138240, while the sum is 40.

The square root of 85661644 is about 9255.3575835837. The cubic root of 85661644 is about 440.8208574753.

It can be divided in two parts, 856 and 61644, that added together give a square (62500 = 250²).

The spelling of 85661644 in words is "eighty-five million, six hundred sixty-one thousand, six hundred forty-four".