51891899 has 2 divisors, whose sum is σ = 51891900. Its totient is φ = 51891898.

The previous prime is 51891883. The next prime is 51891911. The reversal of 51891899 is 99819815.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51891899 - 2⁴ = 51891883 is a prime.

It is not a weakly prime, because it can be changed into another prime (51891809) 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, 25945949 + 25945950.

It is an arithmetic number, because the mean of its divisors is an integer number (25945950).

Almost surely, 2^51891899 is an apocalyptic number.

51891899 is a deficient number, since it is larger than the sum of its proper divisors (1).

51891899 is an equidigital number, since it uses as much as digits as its factorization.

51891899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 50.

The square root of 51891899 is about 7203.6031956237. The cubic root of 51891899 is about 372.9922899695.

The spelling of 51891899 in words is "fifty-one million, eight hundred ninety-one thousand, eight hundred ninety-nine".