51871999 has 2 divisors, whose sum is σ = 51872000. Its totient is φ = 51871998.

The previous prime is 51871993. The next prime is 51872017. The reversal of 51871999 is 99917815.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51871999 - 2⁷ = 51871871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51871993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25935999 + 25936000.

It is an arithmetic number, because the mean of its divisors is an integer number (25936000).

Almost surely, 2^51871999 is an apocalyptic number.

51871999 is a deficient number, since it is larger than the sum of its proper divisors (1).

51871999 is an equidigital number, since it uses as much as digits as its factorization.

51871999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 49.

The square root of 51871999 is about 7202.2218099695. The cubic root of 51871999 is about 372.9446043272.

The spelling of 51871999 in words is "fifty-one million, eight hundred seventy-one thousand, nine hundred ninety-nine".