85220720 has 40 divisors (see below), whose sum is σ = 213382176. Its totient is φ = 31465728.

The previous prime is 85220701. The next prime is 85220749. The reversal of 85220720 is 2702258.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×85220720² = 14525142234636800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 85220720.

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, 39932 + ... + 42011.

Almost surely, 2^85220720 is an apocalyptic number.

85220720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

85220720 is an abundant number, since it is smaller than the sum of its proper divisors (128161456).

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

85220720 is a wasteful number, since it uses less digits than its factorization.

85220720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81969 (or 81963 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 85220720 is about 9231.5069192413. The cubic root of 85220720 is about 440.0632140582.

Adding to 85220720 its reverse (2702258), we get a palindrome (87922978).

The spelling of 85220720 in words is "eighty-five million, two hundred twenty thousand, seven hundred twenty".