505491993 has 12 divisors (see below), whose sum is σ = 747964308. Its totient is φ = 328775040.

The previous prime is 505491989. The next prime is 505492021. The reversal of 505491993 is 399194505.

It is a happy number.

505491993 is a `hidden beast` number, since 5 + 0 + 549 + 19 + 93 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 33212169 + 472279824 = 5763^2 + 21732^2 .

It is not a de Polignac number, because 505491993 - 2² = 505491989 is a prime.

It is a super-2 number, since 2×505491993² = 511044309974224098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (505491193) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 684580 + ... + 685317.

It is an arithmetic number, because the mean of its divisors is an integer number (62330359).

Almost surely, 2^505491993 is an apocalyptic number.

It is an amenable number.

505491993 is a deficient number, since it is larger than the sum of its proper divisors (242472315).

505491993 is a wasteful number, since it uses less digits than its factorization.

505491993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369944 (or 1369941 counting only the distinct ones).

The product of its (nonzero) digits is 218700, while the sum is 45.

The square root of 505491993 is about 22483.1490899296. The cubic root of 505491993 is about 796.5959491119.

The spelling of 505491993 in words is "five hundred five million, four hundred ninety-one thousand, nine hundred ninety-three".