51091949 has 2 divisors, whose sum is σ = 51091950. Its totient is φ = 51091948.

The previous prime is 51091921. The next prime is 51091967. The reversal of 51091949 is 94919015.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50055625 + 1036324 = 7075^2 + 1018^2 .

It is a cyclic number.

It is not a de Polignac number, because 51091949 - 2⁸ = 51091693 is a prime.

It is a super-2 number, since 2×51091949² = 5220774505237202, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51091979) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25545974 + 25545975.

It is an arithmetic number, because the mean of its divisors is an integer number (25545975).

Almost surely, 2^51091949 is an apocalyptic number.

It is an amenable number.

51091949 is a deficient number, since it is larger than the sum of its proper divisors (1).

51091949 is an equidigital number, since it uses as much as digits as its factorization.

51091949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14580, while the sum is 38.

The square root of 51091949 is about 7147.8632471530. The cubic root of 51091949 is about 371.0657100573.

The spelling of 51091949 in words is "fifty-one million, ninety-one thousand, nine hundred forty-nine".