55020191 has 2 divisors, whose sum is σ = 55020192. Its totient is φ = 55020190.

The previous prime is 55020169. The next prime is 55020193. The reversal of 55020191 is 19102055.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55020191 is a prime.

It is a Sophie Germain prime.

Together with 55020193, 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 (55020193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27510095 + 27510096.

It is an arithmetic number, because the mean of its divisors is an integer number (27510096).

Almost surely, 2^55020191 is an apocalyptic number.

55020191 is a deficient number, since it is larger than the sum of its proper divisors (1).

55020191 is an equidigital number, since it uses as much as digits as its factorization.

55020191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 55020191 is about 7417.5596391266. The cubic root of 55020191 is about 380.3417769967.

It can be divided in two parts, 55020 and 191, that multiplied together give a triangular number (10508820 = T₄₅₈₄).

The spelling of 55020191 in words is "fifty-five million, twenty thousand, one hundred ninety-one".