51081864 has 32 divisors (see below), whose sum is σ = 128008320. Its totient is φ = 16986816.

The previous prime is 51081851. The next prime is 51081911. The reversal of 51081864 is 46818015.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 8814 + ... + 13410.

It is an arithmetic number, because the mean of its divisors is an integer number (4000260).

Almost surely, 2^51081864 is an apocalyptic number.

It is an amenable number.

51081864 is an abundant number, since it is smaller than the sum of its proper divisors (76926456).

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

51081864 is a wasteful number, since it uses less digits than its factorization.

51081864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5069 (or 5065 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 51081864 is about 7147.1577567590. The cubic root of 51081864 is about 371.0412936603.

Adding to 51081864 its reverse (46818015), we get a palindrome (97899879).

The spelling of 51081864 in words is "fifty-one million, eighty-one thousand, eight hundred sixty-four".