51138211 has 4 divisors (see below), whose sum is σ = 51196752. Its totient is φ = 51079672.

The previous prime is 51138173. The next prime is 51138221. The reversal of 51138211 is 11283115.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11283115 = 5 ⋅2256623.

It is a cyclic number.

It is not a de Polignac number, because 51138211 - 2⁷ = 51138083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51138221) 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, 27940 + ... + 29713.

It is an arithmetic number, because the mean of its divisors is an integer number (12799188).

Almost surely, 2^51138211 is an apocalyptic number.

51138211 is a deficient number, since it is larger than the sum of its proper divisors (58541).

51138211 is an equidigital number, since it uses as much as digits as its factorization.

51138211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58540.

The product of its digits is 240, while the sum is 22.

The square root of 51138211 is about 7151.0985869305. The cubic root of 51138211 is about 371.1776720113.

The spelling of 51138211 in words is "fifty-one million, one hundred thirty-eight thousand, two hundred eleven".