51429991 has 2 divisors, whose sum is σ = 51429992. Its totient is φ = 51429990.

The previous prime is 51429977. The next prime is 51430003. The reversal of 51429991 is 19992415.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51429991 - 2¹⁹ = 50905703 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 (51429901) 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, 25714995 + 25714996.

It is an arithmetic number, because the mean of its divisors is an integer number (25714996).

Almost surely, 2^51429991 is an apocalyptic number.

51429991 is a deficient number, since it is larger than the sum of its proper divisors (1).

51429991 is an equidigital number, since it uses as much as digits as its factorization.

51429991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160, while the sum is 40.

The square root of 51429991 is about 7171.4706302125. The cubic root of 51429991 is about 371.8822781430.

The spelling of 51429991 in words is "fifty-one million, four hundred twenty-nine thousand, nine hundred ninety-one".