51091000281 has 24 divisors (see below), whose sum is σ = 74955576384. Its totient is φ = 33527213280.

The previous prime is 51091000253. The next prime is 51091000291. The reversal of 51091000281 is 18200019015.

It is not a de Polignac number, because 51091000281 - 2⁵ = 51091000249 is a prime.

It is a super-2 number, since 2×51091000281² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51091000291) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 793311 + ... + 855291.

It is an arithmetic number, because the mean of its divisors is an integer number (3123149016).

Almost surely, 2^51091000281 is an apocalyptic number.

It is an amenable number.

51091000281 is a deficient number, since it is larger than the sum of its proper divisors (23864576103).

51091000281 is a wasteful number, since it uses less digits than its factorization.

51091000281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63421 (or 63418 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

Adding to 51091000281 its reverse (18200019015), we get a palindrome (69291019296).

The spelling of 51091000281 in words is "fifty-one billion, ninety-one million, two hundred eighty-one", and thus it is an aban number.