51100085721 has 16 divisors (see below), whose sum is σ = 68583947328. Its totient is φ = 33841579200.

The previous prime is 51100085713. The next prime is 51100085723. The reversal of 51100085721 is 12758000115.

It is not a de Polignac number, because 51100085721 - 2³ = 51100085713 is a prime.

It is a super-2 number, since 2×51100085721² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51100085723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2425051 + ... + 2446031.

It is an arithmetic number, because the mean of its divisors is an integer number (4286496708).

Almost surely, 2^51100085721 is an apocalyptic number.

It is an amenable number.

51100085721 is a deficient number, since it is larger than the sum of its proper divisors (17483861607).

51100085721 is a wasteful number, since it uses less digits than its factorization.

51100085721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26312.

The product of its (nonzero) digits is 2800, while the sum is 30.

Adding to 51100085721 its reverse (12758000115), we get a palindrome (63858085836).

The spelling of 51100085721 in words is "fifty-one billion, one hundred million, eighty-five thousand, seven hundred twenty-one".