393979505 has 16 divisors (see below), whose sum is σ = 501195600. Its totient is φ = 296282112.

The previous prime is 393979499. The next prime is 393979511. The reversal of 393979505 is 505979393.

It is an interprime number because it is at equal distance from previous prime (393979499) and next prime (393979511).

It can be written as a sum of positive squares in 8 ways, for example, as 124724224 + 269255281 = 11168^2 + 16409^2 .

It is a cyclic number.

It is not a de Polignac number, because 393979505 - 2⁸ = 393979249 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82421 + ... + 87069.

It is an arithmetic number, because the mean of its divisors is an integer number (31324725).

Almost surely, 2^393979505 is an apocalyptic number.

It is an amenable number.

393979505 is a deficient number, since it is larger than the sum of its proper divisors (107216095).

393979505 is a wasteful number, since it uses less digits than its factorization.

393979505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5668.

The product of its (nonzero) digits is 1148175, while the sum is 50.

The square root of 393979505 is about 19848.9169729736. The cubic root of 393979505 is about 733.0909813259.

The spelling of 393979505 in words is "three hundred ninety-three million, nine hundred seventy-nine thousand, five hundred five".