85639820 has 48 divisors (see below), whose sum is σ = 206165568. Its totient is φ = 29272320.

The previous prime is 85639811. The next prime is 85639837. The reversal of 85639820 is 2893658.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58214 + ... + 59666.

It is an arithmetic number, because the mean of its divisors is an integer number (4295116).

Almost surely, 2^85639820 is an apocalyptic number.

It is an amenable number.

85639820 is an abundant number, since it is smaller than the sum of its proper divisors (120525748).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

85639820 is a wasteful number, since it uses less digits than its factorization.

85639820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1890 (or 1888 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 85639820 is about 9254.1785156760. The cubic root of 85639820 is about 440.7834183483.

The spelling of 85639820 in words is "eighty-five million, six hundred thirty-nine thousand, eight hundred twenty".