51123551 has 4 divisors (see below), whose sum is σ = 51961704. Its totient is φ = 50285400.

The previous prime is 51123511. The next prime is 51123599. The reversal of 51123551 is 15532115.

It is a happy number.

51123551 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 an emirpimes, since its reverse is a distinct semiprime: 15532115 = 5 ⋅3106423.

It is a cyclic number.

It is not a de Polignac number, because 51123551 - 2⁶ = 51123487 is a prime.

It is a super-2 number, since 2×51123551² = 5227234933699202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51123511) 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, 418985 + ... + 419106.

It is an arithmetic number, because the mean of its divisors is an integer number (12990426).

Almost surely, 2^51123551 is an apocalyptic number.

51123551 is a deficient number, since it is larger than the sum of its proper divisors (838153).

51123551 is an equidigital number, since it uses as much as digits as its factorization.

51123551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838152.

The product of its digits is 750, while the sum is 23.

The square root of 51123551 is about 7150.0734961258. The cubic root of 51123551 is about 371.1421996146.

Adding to 51123551 its reverse (15532115), we get a palindrome (66655666).

The spelling of 51123551 in words is "fifty-one million, one hundred twenty-three thousand, five hundred fifty-one".