505549981 has 8 divisors (see below), whose sum is σ = 520183520. Its totient is φ = 490967568.

The previous prime is 505549973. The next prime is 505549999. The reversal of 505549981 is 189945505.

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

It is a cyclic number.

It is not a de Polignac number, because 505549981 - 2³ = 505549973 is a prime.

It is a super-2 number, since 2×505549981² = 511161566578200722, 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 (505549901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7750 + ... + 32728.

It is an arithmetic number, because the mean of its divisors is an integer number (65022940).

Almost surely, 2^505549981 is an apocalyptic number.

It is an amenable number.

505549981 is a deficient number, since it is larger than the sum of its proper divisors (14633539).

505549981 is a wasteful number, since it uses less digits than its factorization.

505549981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25563.

The product of its (nonzero) digits is 324000, while the sum is 46.

The square root of 505549981 is about 22484.4386409801. The cubic root of 505549981 is about 796.6264087039.

The spelling of 505549981 in words is "five hundred five million, five hundred forty-nine thousand, nine hundred eighty-one".