53081991 has 24 divisors (see below), whose sum is σ = 82246320. Its totient is φ = 32887296.

The previous prime is 53081981. The next prime is 53081993. The reversal of 53081991 is 19918035.

It is a happy number.

It is not a de Polignac number, because 53081991 - 2⁶ = 53081927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53081993) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6135 + ... + 11991.

It is an arithmetic number, because the mean of its divisors is an integer number (3426930).

Almost surely, 2^53081991 is an apocalyptic number.

53081991 is a deficient number, since it is larger than the sum of its proper divisors (29164329).

53081991 is a wasteful number, since it uses less digits than its factorization.

53081991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5935 (or 5932 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 53081991 is about 7285.7388781098. The cubic root of 53081991 is about 375.8221747591.

The spelling of 53081991 in words is "fifty-three million, eighty-one thousand, nine hundred ninety-one".