494557781 has 8 divisors (see below), whose sum is σ = 500952600. Its totient is φ = 488181760.

The previous prime is 494557771. The next prime is 494557801. The reversal of 494557781 is 187755494.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 87123556 + 407434225 = 9334^2 + 20185^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-494557781 is a prime.

It is a super-2 number, since 2×494557781² = 489174797495287922, 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 (494557771) 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 7 ways as a sum of consecutive naturals, for example, 52715 + ... + 61383.

It is an arithmetic number, because the mean of its divisors is an integer number (62619075).

Almost surely, 2^494557781 is an apocalyptic number.

It is an amenable number.

494557781 is a deficient number, since it is larger than the sum of its proper divisors (6394819).

494557781 is an equidigital number, since it uses as much as digits as its factorization.

494557781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9399.

The product of its digits is 1411200, while the sum is 50.

The square root of 494557781 is about 22238.6551077173. The cubic root of 494557781 is about 790.8103531244.

It can be divided in two parts, 4945 and 57781, that added together give a palindrome (62726).

The spelling of 494557781 in words is "four hundred ninety-four million, five hundred fifty-seven thousand, seven hundred eighty-one".