542781 has 10 divisors (see below), whose sum is σ = 810942. Its totient is φ = 361800.

The previous prime is 542771. The next prime is 542783. The reversal of 542781 is 187245.

It can be written as a sum of positive squares in only one way, i.e., 443556 + 99225 = 666^2 + 315^2 .

It is not a de Polignac number, because 542781 - 2¹⁴ = 526397 is a prime.

It is a super-2 number, since 2×542781² = 589222427922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

542781 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 542781.

It is not an unprimeable number, because it can be changed into a prime (542783) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3270 + ... + 3431.

2⁵⁴²⁷⁸¹ is an apocalyptic number.

It is an amenable number.

542781 is a deficient number, since it is larger than the sum of its proper divisors (268161).

542781 is an equidigital number, since it uses as much as digits as its factorization.

542781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6713 (or 6704 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 542781 is about 736.7367236673. The cubic root of 542781 is about 81.5720817122.

The spelling of 542781 in words is "five hundred forty-two thousand, seven hundred eighty-one".