53851991 has 4 divisors (see below), whose sum is σ = 55589184. Its totient is φ = 52114800.

The previous prime is 53851981. The next prime is 53851997. The reversal of 53851991 is 19915835.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 53851991 - 2¹⁰ = 53850967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53851997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 868550 + ... + 868611.

It is an arithmetic number, because the mean of its divisors is an integer number (13897296).

Almost surely, 2^53851991 is an apocalyptic number.

53851991 is a deficient number, since it is larger than the sum of its proper divisors (1737193).

53851991 is a wasteful number, since it uses less digits than its factorization.

53851991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1737192.

The product of its digits is 48600, while the sum is 41.

The square root of 53851991 is about 7338.3915812663. The cubic root of 53851991 is about 377.6306662850.

The spelling of 53851991 in words is "fifty-three million, eight hundred fifty-one thousand, nine hundred ninety-one".