51121521 has 24 divisors (see below), whose sum is σ = 82083456. Its totient is φ = 30395040.

The previous prime is 51121513. The next prime is 51121523. The reversal of 51121521 is 12512115.

51121521 is a `hidden beast` number, since 511 + 2 + 152 + 1 = 666.

It is not a de Polignac number, because 51121521 - 2³ = 51121513 is a prime.

It is a super-2 number, since 2×51121521² = 5226819818706882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51121494 and 51121503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51121523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 376 + ... + 10118.

It is an arithmetic number, because the mean of its divisors is an integer number (3420144).

Almost surely, 2^51121521 is an apocalyptic number.

It is an amenable number.

51121521 is a deficient number, since it is larger than the sum of its proper divisors (30961935).

51121521 is a wasteful number, since it uses less digits than its factorization.

51121521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9813 (or 9810 counting only the distinct ones).

The product of its digits is 100, while the sum is 18.

The square root of 51121521 is about 7149.9315381338. The cubic root of 51121521 is about 371.1372871452.

Adding to 51121521 its reverse (12512115), we get a palindrome (63633636).

The spelling of 51121521 in words is "fifty-one million, one hundred twenty-one thousand, five hundred twenty-one".