20443665 has 32 divisors (see below), whose sum is σ = 37241856. Its totient is φ = 9479360.

The previous prime is 20443627. The next prime is 20443667. The reversal of 20443665 is 56634402.

It is not a de Polignac number, because 20443665 - 2¹² = 20439569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20443667) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1102 + ... + 6488.

It is an arithmetic number, because the mean of its divisors is an integer number (1163808).

Almost surely, 2^20443665 is an apocalyptic number.

It is an amenable number.

20443665 is a deficient number, since it is larger than the sum of its proper divisors (16798191).

20443665 is a wasteful number, since it uses less digits than its factorization.

20443665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5429.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 20443665 is about 4521.4671291518. The cubic root of 20443665 is about 273.4342536649.

The spelling of 20443665 in words is "twenty million, four hundred forty-three thousand, six hundred sixty-five".