85621520 has 80 divisors (see below), whose sum is σ = 212651568. Its totient is φ = 31948800.

The previous prime is 85621517. The next prime is 85621559. The reversal of 85621520 is 2512658.

It can be written as a sum of positive squares in 8 ways, for example, as 8111104 + 77510416 = 2848^2 + 8804^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×85621520² = 14662089374220800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 213320 + ... + 213720.

Almost surely, 2^85621520 is an apocalyptic number.

85621520 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 85621520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106325784).

85621520 is an abundant number, since it is smaller than the sum of its proper divisors (127030048).

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

85621520 is a wasteful number, since it uses less digits than its factorization.

85621520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 85621520 is about 9253.1897203073. The cubic root of 85621520 is about 440.7520197490.

The spelling of 85621520 in words is "eighty-five million, six hundred twenty-one thousand, five hundred twenty".