505799987 has 16 divisors (see below), whose sum is σ = 631352832. Its totient is φ = 393664320.

The previous prime is 505799977. The next prime is 505799989. The reversal of 505799987 is 789997505.

It is not a de Polignac number, because 505799987 - 2¹⁸ = 505537843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (505799989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71063 + ... + 77855.

It is an arithmetic number, because the mean of its divisors is an integer number (39459552).

Almost surely, 2^505799987 is an apocalyptic number.

505799987 is a deficient number, since it is larger than the sum of its proper divisors (125552845).

505799987 is a wasteful number, since it uses less digits than its factorization.

505799987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7778.

The product of its (nonzero) digits is 7144200, while the sum is 59.

The square root of 505799987 is about 22489.9974877722. The cubic root of 505799987 is about 796.7577037083.

The spelling of 505799987 in words is "five hundred five million, seven hundred ninety-nine thousand, nine hundred eighty-seven".