53991143 has 4 divisors (see below), whose sum is σ = 56338608. Its totient is φ = 51643680.

The previous prime is 53991139. The next prime is 53991149. The reversal of 53991143 is 34119935.

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 53991143 - 2² = 53991139 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 (53991149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1173698 + ... + 1173743.

It is an arithmetic number, because the mean of its divisors is an integer number (14084652).

Almost surely, 2^53991143 is an apocalyptic number.

53991143 is a deficient number, since it is larger than the sum of its proper divisors (2347465).

53991143 is a wasteful number, since it uses less digits than its factorization.

53991143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2347464.

The product of its digits is 14580, while the sum is 35.

The square root of 53991143 is about 7347.8665611183. The cubic root of 53991143 is about 377.9556488001.

The spelling of 53991143 in words is "fifty-three million, nine hundred ninety-one thousand, one hundred forty-three".