54171991 has 2 divisors, whose sum is σ = 54171992. Its totient is φ = 54171990.

The previous prime is 54171937. The next prime is 54172003. The reversal of 54171991 is 19917145.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 54171991 - 2⁷ = 54171863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 54171991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54178991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27085995 + 27085996.

It is an arithmetic number, because the mean of its divisors is an integer number (27085996).

Almost surely, 2^54171991 is an apocalyptic number.

54171991 is a deficient number, since it is larger than the sum of its proper divisors (1).

54171991 is an equidigital number, since it uses as much as digits as its factorization.

54171991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11340, while the sum is 37.

The square root of 54171991 is about 7360.1624302729. The cubic root of 54171991 is about 378.3771768726.

The spelling of 54171991 in words is "fifty-four million, one hundred seventy-one thousand, nine hundred ninety-one".