51081390 has 48 divisors (see below), whose sum is σ = 138591648. Its totient is φ = 13028928.

The previous prime is 51081389. The next prime is 51081467. The reversal of 51081390 is 9318015.

51081390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 10269 + ... + 14408.

It is an arithmetic number, because the mean of its divisors is an integer number (2887326).

Almost surely, 2^51081390 is an apocalyptic number.

51081390 is an abundant number, since it is smaller than the sum of its proper divisors (87510258).

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

51081390 is a wasteful number, since it uses less digits than its factorization.

51081390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24713 (or 24710 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 51081390 is about 7147.1245966472. The cubic root of 51081390 is about 371.0401459984.

The spelling of 51081390 in words is "fifty-one million, eighty-one thousand, three hundred ninety".