51437221 has 6 divisors (see below), whose sum is σ = 56538566. Its totient is φ = 46761000.

The previous prime is 51437219. The next prime is 51437251. The reversal of 51437221 is 12273415.

It is a happy number.

51437221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 51122500 + 314721 = 7150^2 + 561^2 .

It is not a de Polignac number, because 51437221 - 2¹ = 51437219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51437251) 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 5 ways as a sum of consecutive naturals, for example, 212430 + ... + 212671.

Almost surely, 2^51437221 is an apocalyptic number.

It is an amenable number.

51437221 is a deficient number, since it is larger than the sum of its proper divisors (5101345).

51437221 is a wasteful number, since it uses less digits than its factorization.

51437221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425123 (or 425112 counting only the distinct ones).

The product of its digits is 1680, while the sum is 25.

The square root of 51437221 is about 7171.9746932069. The cubic root of 51437221 is about 371.8997036622.

The spelling of 51437221 in words is "fifty-one million, four hundred thirty-seven thousand, two hundred twenty-one".