545291991 has 18 divisors (see below), whose sum is σ = 795504528. Its totient is φ = 359935560.

The previous prime is 545291947. The next prime is 545292023. The reversal of 545291991 is 199192545.

545291991 is a `hidden beast` number, since 5 + 452 + 9 + 199 + 1 = 666.

It is not a de Polignac number, because 545291991 - 2²⁵ = 511737559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (545291911) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 92626 + ... + 98336.

It is an arithmetic number, because the mean of its divisors is an integer number (44194696).

Almost surely, 2^545291991 is an apocalyptic number.

545291991 is a deficient number, since it is larger than the sum of its proper divisors (250212537).

545291991 is a wasteful number, since it uses less digits than its factorization.

545291991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5923 (or 5817 counting only the distinct ones).

The product of its digits is 145800, while the sum is 45.

The square root of 545291991 is about 23351.4879825676. The cubic root of 545291991 is about 816.9767669964.

The spelling of 545291991 in words is "five hundred forty-five million, two hundred ninety-one thousand, nine hundred ninety-one".