51261818 has 12 divisors (see below), whose sum is σ = 77398650. Its totient is φ = 25463160.

The previous prime is 51261797. The next prime is 51261823. The reversal of 51261818 is 81816215.

51261818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 38850289 + 12411529 = 6233^2 + 3523^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 146708 + ... + 147056.

Almost surely, 2^51261818 is an apocalyptic number.

51261818 is a deficient number, since it is larger than the sum of its proper divisors (26136832).

51261818 is an equidigital number, since it uses as much as digits as its factorization.

51261818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 893 (or 622 counting only the distinct ones).

The product of its digits is 3840, while the sum is 32.

The square root of 51261818 is about 7159.7358889836. The cubic root of 51261818 is about 371.4764912392.

The spelling of 51261818 in words is "fifty-one million, two hundred sixty-one thousand, eight hundred eighteen".