51509213 has 16 divisors (see below), whose sum is σ = 61648896. Its totient is φ = 42078960.

The previous prime is 51509203. The next prime is 51509221. The reversal of 51509213 is 31290515.

It is not a de Polignac number, because 51509213 - 2⁸ = 51508957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51509203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74198 + ... + 74888.

It is an arithmetic number, because the mean of its divisors is an integer number (3853056).

Almost surely, 2^51509213 is an apocalyptic number.

It is an amenable number.

51509213 is a deficient number, since it is larger than the sum of its proper divisors (10139683).

51509213 is a wasteful number, since it uses less digits than its factorization.

51509213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 51509213 is about 7176.9919186244. The cubic root of 51509213 is about 372.0731275091.

Adding to 51509213 its reverse (31290515), we get a palindrome (82799728).

The spelling of 51509213 in words is "fifty-one million, five hundred nine thousand, two hundred thirteen".