51222991 has 2 divisors, whose sum is σ = 51222992. Its totient is φ = 51222990.

The previous prime is 51222973. The next prime is 51223009. The reversal of 51222991 is 19922215.

It is a balanced prime because it is at equal distance from previous prime (51222973) and next prime (51223009).

It is a cyclic number.

It is not a de Polignac number, because 51222991 - 2¹¹ = 51220943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51222901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25611495 + 25611496.

It is an arithmetic number, because the mean of its divisors is an integer number (25611496).

Almost surely, 2^51222991 is an apocalyptic number.

51222991 is a deficient number, since it is larger than the sum of its proper divisors (1).

51222991 is an equidigital number, since it uses as much as digits as its factorization.

51222991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 31.

The square root of 51222991 is about 7157.0238926526. The cubic root of 51222991 is about 371.3826789805.

The spelling of 51222991 in words is "fifty-one million, two hundred twenty-two thousand, nine hundred ninety-one".