51897221 has 2 divisors, whose sum is σ = 51897222. Its totient is φ = 51897220.

The previous prime is 51897191. The next prime is 51897289. The reversal of 51897221 is 12279815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50608996 + 1288225 = 7114^2 + 1135^2 .

It is a cyclic number.

It is not a de Polignac number, because 51897221 - 2¹⁰ = 51896197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51890221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25948610 + 25948611.

It is an arithmetic number, because the mean of its divisors is an integer number (25948611).

Almost surely, 2^51897221 is an apocalyptic number.

It is an amenable number.

51897221 is a deficient number, since it is larger than the sum of its proper divisors (1).

51897221 is an equidigital number, since it uses as much as digits as its factorization.

51897221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 35.

The square root of 51897221 is about 7203.9725846230. The cubic root of 51897221 is about 373.0050408172.

The spelling of 51897221 in words is "fifty-one million, eight hundred ninety-seven thousand, two hundred twenty-one".