51211913 has 4 divisors (see below), whose sum is σ = 51829008. Its totient is φ = 50594820.

The previous prime is 51211891. The next prime is 51211931. The reversal of 51211913 is 31911215.

51211913 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51211913 - 2¹⁰ = 51210889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51211613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 308423 + ... + 308588.

It is an arithmetic number, because the mean of its divisors is an integer number (12957252).

Almost surely, 2^51211913 is an apocalyptic number.

It is an amenable number.

51211913 is a deficient number, since it is larger than the sum of its proper divisors (617095).

51211913 is an equidigital number, since it uses as much as digits as its factorization.

51211913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617094.

The product of its digits is 270, while the sum is 23.

The square root of 51211913 is about 7156.2499257642. The cubic root of 51211913 is about 371.3559040639.

The spelling of 51211913 in words is "fifty-one million, two hundred eleven thousand, nine hundred thirteen".