20345664 has 28 divisors (see below), whose sum is σ = 53831744. Its totient is φ = 6781824.

The previous prime is 20345659. The next prime is 20345669. The reversal of 20345664 is 46654302.

It is an interprime number because it is at equal distance from previous prime (20345659) and next prime (20345669).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20345669) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 52792 + ... + 53175.

Almost surely, 2^20345664 is an apocalyptic number.

20345664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20345664 is an abundant number, since it is smaller than the sum of its proper divisors (33486080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20345664 is a wasteful number, since it uses less digits than its factorization.

20345664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105982 (or 105972 counting only the distinct ones).

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

The square root of 20345664 is about 4510.6168092623. The cubic root of 20345664 is about 272.9966321419.

Adding to 20345664 its reverse (46654302), we get a palindrome (66999966).

The spelling of 20345664 in words is "twenty million, three hundred forty-five thousand, six hundred sixty-four".