191006551 has 2 divisors, whose sum is σ = 191006552. Its totient is φ = 191006550.

The previous prime is 191006539. The next prime is 191006561. The reversal of 191006551 is 155600191.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 191006551 - 2¹⁷ = 190875479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191006561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95503275 + 95503276.

It is an arithmetic number, because the mean of its divisors is an integer number (95503276).

Almost surely, 2^191006551 is an apocalyptic number.

191006551 is a deficient number, since it is larger than the sum of its proper divisors (1).

191006551 is an equidigital number, since it uses as much as digits as its factorization.

191006551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 28.

The square root of 191006551 is about 13820.5119659150. The cubic root of 191006551 is about 575.9031060894.

It can be divided in two parts, 19100 and 6551, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 191006551 in words is "one hundred ninety-one million, six thousand, five hundred fifty-one".