20865290 has 32 divisors (see below), whose sum is σ = 40098240. Its totient is φ = 7789824.

The previous prime is 20865283. The next prime is 20865311. The reversal of 20865290 is 9256802.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23189 + ... + 24071.

It is an arithmetic number, because the mean of its divisors is an integer number (1253070).

Almost surely, 2^20865290 is an apocalyptic number.

20865290 is a deficient number, since it is larger than the sum of its proper divisors (19232950).

20865290 is a wasteful number, since it uses less digits than its factorization.

20865290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 20865290 is about 4567.8539819044. The cubic root of 20865290 is about 275.3012236506.

The spelling of 20865290 in words is "twenty million, eight hundred sixty-five thousand, two hundred ninety".