51294221 has 4 divisors (see below), whose sum is σ = 55957344. Its totient is φ = 46631100.

The previous prime is 51294211. The next prime is 51294223. The reversal of 51294221 is 12249215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51294221 - 2¹⁸ = 51032077 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 (51294223) 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 3 ways as a sum of consecutive naturals, for example, 2331545 + ... + 2331566.

It is an arithmetic number, because the mean of its divisors is an integer number (13989336).

Almost surely, 2^51294221 is an apocalyptic number.

It is an amenable number.

51294221 is a deficient number, since it is larger than the sum of its proper divisors (4663123).

51294221 is a wasteful number, since it uses less digits than its factorization.

51294221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4663122.

The product of its digits is 1440, while the sum is 26.

The square root of 51294221 is about 7161.9983943031. The cubic root of 51294221 is about 371.5547458277.

It can be divided in two parts, 51294 and 221, that added together give a palindrome (51515).

The spelling of 51294221 in words is "fifty-one million, two hundred ninety-four thousand, two hundred twenty-one".