51620197 has 2 divisors, whose sum is σ = 51620198. Its totient is φ = 51620196.

The previous prime is 51620161. The next prime is 51620209. The reversal of 51620197 is 79102615.

51620197 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39551521 + 12068676 = 6289^2 + 3474^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51620197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51620137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25810098 + 25810099.

It is an arithmetic number, because the mean of its divisors is an integer number (25810099).

Almost surely, 2^51620197 is an apocalyptic number.

It is an amenable number.

51620197 is a deficient number, since it is larger than the sum of its proper divisors (1).

51620197 is an equidigital number, since it uses as much as digits as its factorization.

51620197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 51620197 is about 7184.7196883386. The cubic root of 51620197 is about 372.3401641482.

The spelling of 51620197 in words is "fifty-one million, six hundred twenty thousand, one hundred ninety-seven".