85649840640 has 1920 divisors, whose sum is σ = 405379054080. Its totient is φ = 16817061888.

The previous prime is 85649840597. The next prime is 85649840641. The reversal of 85649840640 is 4604894658.

85649840640 is a `hidden beast` number, since 8 + 56 + 498 + 40 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85649840641) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 962357716 + ... + 962357804.

It is an arithmetic number, because the mean of its divisors is an integer number (211134924).

Almost surely, 2^85649840640 is an apocalyptic number.

85649840640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 85649840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202689527040).

85649840640 is an abundant number, since it is smaller than the sum of its proper divisors (319729213440).

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

85649840640 is a wasteful number, since it uses less digits than its factorization.

85649840640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 54.

The spelling of 85649840640 in words is "eighty-five billion, six hundred forty-nine million, eight hundred forty thousand, six hundred forty".