51909005 has 4 divisors (see below), whose sum is σ = 62290812. Its totient is φ = 41527200.

The previous prime is 51909001. The next prime is 51909019. The reversal of 51909005 is 50090915.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22250089 + 29658916 = 4717^2 + 5446^2 .

It is not a de Polignac number, because 51909005 - 2² = 51909001 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51909001) 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, 5190896 + ... + 5190905.

It is an arithmetic number, because the mean of its divisors is an integer number (15572703).

Almost surely, 2^51909005 is an apocalyptic number.

It is an amenable number.

51909005 is a deficient number, since it is larger than the sum of its proper divisors (10381807).

51909005 is a wasteful number, since it uses less digits than its factorization.

51909005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10381806.

The product of its (nonzero) digits is 2025, while the sum is 29.

The square root of 51909005 is about 7204.7904202690. The cubic root of 51909005 is about 373.0332707087.

The spelling of 51909005 in words is "fifty-one million, nine hundred nine thousand, five".