51352821 has 12 divisors (see below), whose sum is σ = 79882348. Its totient is φ = 31601664.

The previous prime is 51352783. The next prime is 51352841. The reversal of 51352821 is 12825315.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6275025 + 45077796 = 2505^2 + 6714^2 .

It is not a de Polignac number, because 51352821 - 2⁶ = 51352757 is a prime.

It is a super-2 number, since 2×51352821² = 5274224449316082, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51352841) 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, 219340 + ... + 219573.

Almost surely, 2^51352821 is an apocalyptic number.

It is an amenable number.

51352821 is a deficient number, since it is larger than the sum of its proper divisors (28529527).

51352821 is a wasteful number, since it uses less digits than its factorization.

51352821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438932 (or 438929 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 51352821 is about 7166.0882634810. The cubic root of 51352821 is about 371.6961836058.

The spelling of 51352821 in words is "fifty-one million, three hundred fifty-two thousand, eight hundred twenty-one".