51081808 has 10 divisors (see below), whose sum is σ = 98971034. Its totient is φ = 25540896.

The previous prime is 51081803. The next prime is 51081829. The reversal of 51081808 is 80818015.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 50580544 + 501264 = 7112^2 + 708^2 .

It is a super-2 number, since 2×51081808² = 5218702217097728, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51081808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51081803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1596291 + ... + 1596322.

Almost surely, 2^51081808 is an apocalyptic number.

It is an amenable number.

51081808 is a deficient number, since it is larger than the sum of its proper divisors (47889226).

51081808 is a wasteful number, since it uses less digits than its factorization.

51081808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3192621 (or 3192615 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 31.

The square root of 51081808 is about 7147.1538391167. The cubic root of 51081808 is about 371.0411580719.

The spelling of 51081808 in words is "fifty-one million, eighty-one thousand, eight hundred eight".