503905681 has 4 divisors (see below), whose sum is σ = 504218164. Its totient is φ = 503593200.

The previous prime is 503905639. The next prime is 503905729. The reversal of 503905681 is 186509305.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186509305 = 5 ⋅37301861.

It can be written as a sum of positive squares in 2 ways, for example, as 361342081 + 142563600 = 19009^2 + 11940^2 .

It is a cyclic number.

It is not a de Polignac number, because 503905681 - 2⁹ = 503905169 is a prime.

It is a super-2 number, since 2×503905681² = 507841870688147522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 503905681.

It is not an unprimeable number, because it can be changed into a prime (503905601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153810 + ... + 157051.

It is an arithmetic number, because the mean of its divisors is an integer number (126054541).

Almost surely, 2^503905681 is an apocalyptic number.

It is an amenable number.

503905681 is a deficient number, since it is larger than the sum of its proper divisors (312483).

503905681 is a wasteful number, since it uses less digits than its factorization.

503905681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312482.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 503905681 is about 22447.8435712654. The cubic root of 503905681 is about 795.7617955329.

The spelling of 503905681 in words is "five hundred three million, nine hundred five thousand, six hundred eighty-one".