20842665 has 8 divisors (see below), whose sum is σ = 33348288. Its totient is φ = 11116080.

The previous prime is 20842631. The next prime is 20842673. The reversal of 20842665 is 56624802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20842665 - 2¹² = 20838569 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 694741 + ... + 694770.

It is an arithmetic number, because the mean of its divisors is an integer number (4168536).

Almost surely, 2^20842665 is an apocalyptic number.

It is an amenable number.

20842665 is a deficient number, since it is larger than the sum of its proper divisors (12505623).

20842665 is a wasteful number, since it uses less digits than its factorization.

20842665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389519.

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 20842665 is about 4565.3767642989. The cubic root of 20842665 is about 275.2016812547.

The spelling of 20842665 in words is "twenty million, eight hundred forty-two thousand, six hundred sixty-five".