51198209 has 2 divisors, whose sum is σ = 51198210. Its totient is φ = 51198208.

The previous prime is 51198197. The next prime is 51198221. The reversal of 51198209 is 90289115.

It is a balanced prime because it is at equal distance from previous prime (51198197) and next prime (51198221).

It can be written as a sum of positive squares in only one way, i.e., 46036225 + 5161984 = 6785^2 + 2272^2 .

It is a cyclic number.

It is not a de Polignac number, because 51198209 - 2²⁴ = 34420993 is a prime.

It is not a weakly prime, because it can be changed into another prime (51198239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25599104 + 25599105.

It is an arithmetic number, because the mean of its divisors is an integer number (25599105).

Almost surely, 2^51198209 is an apocalyptic number.

It is an amenable number.

51198209 is a deficient number, since it is larger than the sum of its proper divisors (1).

51198209 is an equidigital number, since it uses as much as digits as its factorization.

51198209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 51198209 is about 7155.2923769752. The cubic root of 51198209 is about 371.3227769065.

The spelling of 51198209 in words is "fifty-one million, one hundred ninety-eight thousand, two hundred nine".