51797981 has 2 divisors, whose sum is σ = 51797982. Its totient is φ = 51797980.

The previous prime is 51797969. The next prime is 51798007. The reversal of 51797981 is 18979715.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40005625 + 11792356 = 6325^2 + 3434^2 .

It is a cyclic number.

It is not a de Polignac number, because 51797981 - 2⁶ = 51797917 is a prime.

It is a super-2 number, since 2×51797981² = 5366061671352722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51797381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25898990 + 25898991.

It is an arithmetic number, because the mean of its divisors is an integer number (25898991).

Almost surely, 2^51797981 is an apocalyptic number.

It is an amenable number.

51797981 is a deficient number, since it is larger than the sum of its proper divisors (1).

51797981 is an equidigital number, since it uses as much as digits as its factorization.

51797981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 47.

The square root of 51797981 is about 7197.0814223545. The cubic root of 51797981 is about 372.7671305798.

The spelling of 51797981 in words is "fifty-one million, seven hundred ninety-seven thousand, nine hundred eighty-one".