52181813 has 2 divisors, whose sum is σ = 52181814. Its totient is φ = 52181812.

The previous prime is 52181761. The next prime is 52181821. The reversal of 52181813 is 31818125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50794129 + 1387684 = 7127^2 + 1178^2 .

It is a cyclic number.

It is not a de Polignac number, because 52181813 - 2⁶ = 52181749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (52181893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26090906 + 26090907.

It is an arithmetic number, because the mean of its divisors is an integer number (26090907).

Almost surely, 2^52181813 is an apocalyptic number.

It is an amenable number.

52181813 is a deficient number, since it is larger than the sum of its proper divisors (1).

52181813 is an equidigital number, since it uses as much as digits as its factorization.

52181813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 29.

The square root of 52181813 is about 7223.6980141753. The cubic root of 52181813 is about 373.6856218836.

Adding to 52181813 its reverse (31818125), we get a palindrome (83999938).

The spelling of 52181813 in words is "fifty-two million, one hundred eighty-one thousand, eight hundred thirteen".