551041991 has 2 divisors, whose sum is σ = 551041992. Its totient is φ = 551041990.

The previous prime is 551041949. The next prime is 551041993. The reversal of 551041991 is 199140155.

551041991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-551041991 is a prime.

Together with 551041993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (551041993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275520995 + 275520996.

It is an arithmetic number, because the mean of its divisors is an integer number (275520996).

Almost surely, 2^551041991 is an apocalyptic number.

551041991 is a deficient number, since it is larger than the sum of its proper divisors (1).

551041991 is an equidigital number, since it uses as much as digits as its factorization.

551041991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100, while the sum is 35.

The square root of 551041991 is about 23474.2836099422. The cubic root of 551041991 is about 819.8383535224.

The spelling of 551041991 in words is "five hundred fifty-one million, forty-one thousand, nine hundred ninety-one".