85639640 has 32 divisors (see below), whose sum is σ = 196793280. Its totient is φ = 33526272.

The previous prime is 85639637. The next prime is 85639663. The reversal of 85639640 is 4693658.

It is a congruent number.

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, 20897 + ... + 24656.

It is an arithmetic number, because the mean of its divisors is an integer number (6149790).

Almost surely, 2^85639640 is an apocalyptic number.

It is an amenable number.

85639640 is an abundant number, since it is smaller than the sum of its proper divisors (111153640).

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

85639640 is a wasteful number, since it uses less digits than its factorization.

85639640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45611 (or 45607 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 85639640 is about 9254.1687903344. The cubic root of 85639640 is about 440.7831095314.

The spelling of 85639640 in words is "eighty-five million, six hundred thirty-nine thousand, six hundred forty".