51032221 has 2 divisors, whose sum is σ = 51032222. Its totient is φ = 51032220.

The previous prime is 51032207. The next prime is 51032237. The reversal of 51032221 is 12223015.

It is an a-pointer prime, because the next prime (51032237) can be obtained adding 51032221 to its sum of digits (16).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49196196 + 1836025 = 7014^2 + 1355^2 .

It is a cyclic number.

It is not a de Polignac number, because 51032221 - 2¹⁵ = 50999453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51032195 and 51032204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51032251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25516110 + 25516111.

It is an arithmetic number, because the mean of its divisors is an integer number (25516111).

Almost surely, 2^51032221 is an apocalyptic number.

It is an amenable number.

51032221 is a deficient number, since it is larger than the sum of its proper divisors (1).

51032221 is an equidigital number, since it uses as much as digits as its factorization.

51032221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 51032221 is about 7143.6839935708. The cubic root of 51032221 is about 370.9210580773.

Adding to 51032221 its reverse (12223015), we get a palindrome (63255236).

The spelling of 51032221 in words is "fifty-one million, thirty-two thousand, two hundred twenty-one".