51101891 has 2 divisors, whose sum is σ = 51101892. Its totient is φ = 51101890.

The previous prime is 51101863. The next prime is 51101893. The reversal of 51101891 is 19810115.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51101891 - 2¹⁰ = 51100867 is a prime.

It is a super-2 number, since 2×51101891² = 5222806527551762, which contains 22 as substring.

Together with 51101893, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51101891.

It is not a weakly prime, because it can be changed into another prime (51101893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25550945 + 25550946.

It is an arithmetic number, because the mean of its divisors is an integer number (25550946).

Almost surely, 2^51101891 is an apocalyptic number.

51101891 is a deficient number, since it is larger than the sum of its proper divisors (1).

51101891 is an equidigital number, since it uses as much as digits as its factorization.

51101891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 26.

The square root of 51101891 is about 7148.5586659130. The cubic root of 51101891 is about 371.0897770979.

The spelling of 51101891 in words is "fifty-one million, one hundred one thousand, eight hundred ninety-one".