54189781 has 4 divisors (see below), whose sum is σ = 54391500. Its totient is φ = 53988064.

The previous prime is 54189769. The next prime is 54189791. The reversal of 54189781 is 18798145.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2220100 + 51969681 = 1490^2 + 7209^2 .

It is a cyclic number.

It is not a de Polignac number, because 54189781 - 2⁹ = 54189269 is a prime.

It is a super-2 number, since 2×54189781² = 5873064729655922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (54189791) 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, 100456 + ... + 100993.

It is an arithmetic number, because the mean of its divisors is an integer number (13597875).

Almost surely, 2^54189781 is an apocalyptic number.

It is an amenable number.

54189781 is a deficient number, since it is larger than the sum of its proper divisors (201719).

54189781 is a wasteful number, since it uses less digits than its factorization.

54189781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201718.

The product of its digits is 80640, while the sum is 43.

The square root of 54189781 is about 7361.3708641801. The cubic root of 54189781 is about 378.4185918371.

The spelling of 54189781 in words is "fifty-four million, one hundred eighty-nine thousand, seven hundred eighty-one".