51345221 has 4 divisors (see below), whose sum is σ = 51409344. Its totient is φ = 51281100.

The previous prime is 51345199. The next prime is 51345241. The reversal of 51345221 is 12254315.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12254315 = 5 ⋅2450863.

It is a cyclic number.

It is not a de Polignac number, because 51345221 - 2⁶ = 51345157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51345241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30845 + ... + 32466.

It is an arithmetic number, because the mean of its divisors is an integer number (12852336).

Almost surely, 2^51345221 is an apocalyptic number.

It is an amenable number.

51345221 is a deficient number, since it is larger than the sum of its proper divisors (64123).

51345221 is an equidigital number, since it uses as much as digits as its factorization.

51345221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64122.

The product of its digits is 1200, while the sum is 23.

The square root of 51345221 is about 7165.5579685046. The cubic root of 51345221 is about 371.6778462142.

Adding to 51345221 its reverse (12254315), we get a palindrome (63599536).

The spelling of 51345221 in words is "fifty-one million, three hundred forty-five thousand, two hundred twenty-one".