51015881 has 4 divisors (see below), whose sum is σ = 58303872. Its totient is φ = 43727892.

The previous prime is 51015871. The next prime is 51015907. The reversal of 51015881 is 18851015.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51015881 - 2¹⁴ = 50999497 is a prime.

It is a super-2 number, since 2×51015881² = 5205240228412322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51015841) 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 in 3 ways as a sum of consecutive naturals, for example, 3643985 + ... + 3643998.

It is an arithmetic number, because the mean of its divisors is an integer number (14575968).

Almost surely, 2^51015881 is an apocalyptic number.

It is an amenable number.

51015881 is a deficient number, since it is larger than the sum of its proper divisors (7287991).

51015881 is an equidigital number, since it uses as much as digits as its factorization.

51015881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7287990.

The product of its (nonzero) digits is 1600, while the sum is 29.

The square root of 51015881 is about 7142.5402343984. The cubic root of 51015881 is about 370.8814654634.

Adding to 51015881 its reverse (18851015), we get a palindrome (69866896).

The spelling of 51015881 in words is "fifty-one million, fifteen thousand, eight hundred eighty-one".