52181820 has 96 divisors (see below), whose sum is σ = 164485440. Its totient is φ = 13903488.

The previous prime is 52181813. The next prime is 52181821. The reversal of 52181820 is 2818125.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (52181821) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43144 + ... + 44336.

It is an arithmetic number, because the mean of its divisors is an integer number (1713390).

Almost surely, 2^52181820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 52181820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82242720).

52181820 is an abundant number, since it is smaller than the sum of its proper divisors (112303620).

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

52181820 is a wasteful number, since it uses less digits than its factorization.

52181820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1223 (or 1203 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 52181820 is about 7223.6984986917. The cubic root of 52181820 is about 373.6856385931.

Adding to 52181820 its reverse (2818125), we get a palindrome (54999945).

The spelling of 52181820 in words is "fifty-two million, one hundred eighty-one thousand, eight hundred twenty".