85181520 has 80 divisors (see below), whose sum is σ = 266857920. Its totient is φ = 22474752.

The previous prime is 85181519. The next prime is 85181527. The reversal of 85181520 is 2518158.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85181527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21451 + ... + 25109.

It is an arithmetic number, because the mean of its divisors is an integer number (3335724).

Almost surely, 2^85181520 is an apocalyptic number.

85181520 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 85181520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133428960).

85181520 is an abundant number, since it is smaller than the sum of its proper divisors (181676400).

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

85181520 is a wasteful number, since it uses less digits than its factorization.

85181520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3772 (or 3766 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 30.

The square root of 85181520 is about 9229.3835113728. The cubic root of 85181520 is about 439.9957299861.

Adding to 85181520 its reverse (2518158), we get a palindrome (87699678).

The spelling of 85181520 in words is "eighty-five million, one hundred eighty-one thousand, five hundred twenty".