390378565 has 16 divisors (see below), whose sum is σ = 497234160. Its totient is φ = 293207040.

The previous prime is 390378551. The next prime is 390378619. The reversal of 390378565 is 565873093.

It is a Cunningham number, because it is equal to 19758²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 65189476 + 325189089 = 8074^2 + 18033^2 .

It is not a de Polignac number, because 390378565 - 2⁵ = 390378533 is a prime.

It is a super-2 number, since 2×390378565² = 304790848022918450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 30331 + ... + 41239.

It is an arithmetic number, because the mean of its divisors is an integer number (31077135).

Almost surely, 2^390378565 is an apocalyptic number.

It is an amenable number.

390378565 is a deficient number, since it is larger than the sum of its proper divisors (106855595).

390378565 is a wasteful number, since it uses less digits than its factorization.

390378565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11352.

The product of its (nonzero) digits is 680400, while the sum is 46.

The square root of 390378565 is about 19758.0000253062. Note that the first 4 decimals coincide. The cubic root of 390378565 is about 730.8506784154.

The spelling of 390378565 in words is "three hundred ninety million, three hundred seventy-eight thousand, five hundred sixty-five".