51957991 has 2 divisors, whose sum is σ = 51957992. Its totient is φ = 51957990.

The previous prime is 51957979. The next prime is 51958003. The reversal of 51957991 is 19975915.

51957991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (51957979) and next prime (51958003).

It is a cyclic number.

It is not a de Polignac number, because 51957991 - 2⁵ = 51957959 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51957901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25978995 + 25978996.

It is an arithmetic number, because the mean of its divisors is an integer number (25978996).

Almost surely, 2^51957991 is an apocalyptic number.

51957991 is a deficient number, since it is larger than the sum of its proper divisors (1).

51957991 is an equidigital number, since it uses as much as digits as its factorization.

51957991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127575, while the sum is 46.

The square root of 51957991 is about 7208.1891623347. The cubic root of 51957991 is about 373.1505763841.

The spelling of 51957991 in words is "fifty-one million, nine hundred fifty-seven thousand, nine hundred ninety-one".