85779520 has 56 divisors (see below), whose sum is σ = 205529688. Its totient is φ = 34099200.

The previous prime is 85779517. The next prime is 85779523. The reversal of 85779520 is 2597758.

It is an interprime number because it is at equal distance from previous prime (85779517) and next prime (85779523).

It can be written as a sum of positive squares in 4 ways, for example, as 254016 + 85525504 = 504^2 + 9248^2 .

It is not an unprimeable number, because it can be changed into a prime (85779523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57180 + ... + 58660.

It is an arithmetic number, because the mean of its divisors is an integer number (3670173).

Almost surely, 2^85779520 is an apocalyptic number.

85779520 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 85779520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102764844).

85779520 is an abundant number, since it is smaller than the sum of its proper divisors (119750168).

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

85779520 is a wasteful number, since it uses less digits than its factorization.

85779520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1679 (or 1669 counting only the distinct ones).

The product of its (nonzero) digits is 176400, while the sum is 43.

The square root of 85779520 is about 9261.7233817470. The cubic root of 85779520 is about 441.0229642010.

The spelling of 85779520 in words is "eighty-five million, seven hundred seventy-nine thousand, five hundred twenty".