81772110 has 192 divisors, whose sum is σ = 258785280. Its totient is φ = 17521920.

The previous prime is 81772099. The next prime is 81772123. The reversal of 81772110 is 1127718.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1035051 + ... + 1035129.

It is an arithmetic number, because the mean of its divisors is an integer number (1347840).

Almost surely, 2^81772110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81772110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129392640).

81772110 is an abundant number, since it is smaller than the sum of its proper divisors (177013170).

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

81772110 is a wasteful number, since it uses less digits than its factorization.

81772110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 27.

The square root of 81772110 is about 9042.7932631461. The cubic root of 81772110 is about 434.0453101695.

Adding to 81772110 its reverse (1127718), we get a palindrome (82899828).

It can be divided in two parts, 817 and 72110, that added together give a palindrome (72927).

The spelling of 81772110 in words is "eighty-one million, seven hundred seventy-two thousand, one hundred ten".