51221124 has 36 divisors (see below), whose sum is σ = 129693564. Its totient is φ = 17044992.

The previous prime is 51221123. The next prime is 51221129. The reversal of 51221124 is 42112215.

It can be written as a sum of positive squares in 2 ways, for example, as 38044224 + 13176900 = 6168^2 + 3630^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 51221097 and 51221106.

It is not an unprimeable number, because it can be changed into a prime (51221123) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38844 + ... + 40140.

It is an arithmetic number, because the mean of its divisors is an integer number (3602599).

Almost surely, 2^51221124 is an apocalyptic number.

It is an amenable number.

51221124 is an abundant number, since it is smaller than the sum of its proper divisors (78472440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51221124 is a wasteful number, since it uses less digits than its factorization.

51221124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2404 (or 2399 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 51221124 is about 7156.8934601543. The cubic root of 51221124 is about 371.3781668147.

Adding to 51221124 its reverse (42112215), we get a palindrome (93333339).

The spelling of 51221124 in words is "fifty-one million, two hundred twenty-one thousand, one hundred twenty-four".