51801181 has 2 divisors, whose sum is σ = 51801182. Its totient is φ = 51801180.

The previous prime is 51801179. The next prime is 51801241. The reversal of 51801181 is 18110815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37625956 + 14175225 = 6134^2 + 3765^2 .

It is a cyclic number.

It is not a de Polignac number, because 51801181 - 2¹ = 51801179 is a prime.

It is a super-2 number, since 2×51801181² = 5366724705989522, which contains 22 as substring.

Together with 51801179, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51801131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25900590 + 25900591.

It is an arithmetic number, because the mean of its divisors is an integer number (25900591).

Almost surely, 2^51801181 is an apocalyptic number.

It is an amenable number.

51801181 is a deficient number, since it is larger than the sum of its proper divisors (1).

51801181 is an equidigital number, since it uses as much as digits as its factorization.

51801181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 25.

The square root of 51801181 is about 7197.3037312594. The cubic root of 51801181 is about 372.7748067494.

Adding to 51801181 its reverse (18110815), we get a palindrome (69911996).

The spelling of 51801181 in words is "fifty-one million, eight hundred one thousand, one hundred eighty-one".