81020160 has 216 divisors, whose sum is σ = 302442504. Its totient is φ = 19906560.

The previous prime is 81020131. The next prime is 81020179. The reversal of 81020160 is 6102018.

It can be written as a sum of positive squares in 4 ways, for example, as 451584 + 80568576 = 672^2 + 8976^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 149490 + ... + 150030.

Almost surely, 2^81020160 is an apocalyptic number.

81020160 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 81020160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151221252).

81020160 is an abundant number, since it is smaller than the sum of its proper divisors (221422344).

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

81020160 is a wasteful number, since it uses less digits than its factorization.

81020160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 81020160 is about 9001.1199303198. The cubic root of 81020160 is about 432.7107641039.

Adding to 81020160 its reverse (6102018), we get a palindrome (87122178).

The spelling of 81020160 in words is "eighty-one million, twenty thousand, one hundred sixty".