51381797 has 2 divisors, whose sum is σ = 51381798. Its totient is φ = 51381796.

The previous prime is 51381749. The next prime is 51381809. The reversal of 51381797 is 79718315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26770276 + 24611521 = 5174^2 + 4961^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51381797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51381097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25690898 + 25690899.

It is an arithmetic number, because the mean of its divisors is an integer number (25690899).

Almost surely, 2^51381797 is an apocalyptic number.

It is an amenable number.

51381797 is a deficient number, since it is larger than the sum of its proper divisors (1).

51381797 is an equidigital number, since it uses as much as digits as its factorization.

51381797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52920, while the sum is 41.

The square root of 51381797 is about 7168.1097229325. The cubic root of 51381797 is about 371.7660807301.

The spelling of 51381797 in words is "fifty-one million, three hundred eighty-one thousand, seven hundred ninety-seven".