51985399 has 2 divisors, whose sum is σ = 51985400. Its totient is φ = 51985398.

The previous prime is 51985379. The next prime is 51985403. The reversal of 51985399 is 99358915.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51985399 - 2¹³ = 51977207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51985319) 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, 25992699 + 25992700.

It is an arithmetic number, because the mean of its divisors is an integer number (25992700).

Almost surely, 2^51985399 is an apocalyptic number.

51985399 is a deficient number, since it is larger than the sum of its proper divisors (1).

51985399 is an equidigital number, since it uses as much as digits as its factorization.

51985399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 437400, while the sum is 49.

The square root of 51985399 is about 7210.0900826550. The cubic root of 51985399 is about 373.2161775426.

The spelling of 51985399 in words is "fifty-one million, nine hundred eighty-five thousand, three hundred ninety-nine".