51100009 has 4 divisors (see below), whose sum is σ = 51114580. Its totient is φ = 51085440.

The previous prime is 51099991. The next prime is 51100019. The reversal of 51100009 is 90000115.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 44355600 + 6744409 = 6660^2 + 2597^2 .

It is a cyclic number.

It is not a de Polignac number, because 51100009 - 2⁹ = 51099497 is a prime.

It is a super-2 number, since 2×51100009² = 5222421839600162, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51099965 and 51100001.

It is not an unprimeable number, because it can be changed into a prime (51100019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1537 + ... + 10225.

It is an arithmetic number, because the mean of its divisors is an integer number (12778645).

Almost surely, 2^51100009 is an apocalyptic number.

It is an amenable number.

51100009 is a deficient number, since it is larger than the sum of its proper divisors (14571).

51100009 is an equidigital number, since it uses as much as digits as its factorization.

51100009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14570.

The product of its (nonzero) digits is 45, while the sum is 16.

The square root of 51100009 is about 7148.4270297738. The cubic root of 51100009 is about 371.0852214965.

The spelling of 51100009 in words is "fifty-one million, one hundred thousand, nine".