20231645 has 8 divisors (see below), whose sum is σ = 27746304. Its totient is φ = 13873104.

The previous prime is 20231641. The next prime is 20231657. The reversal of 20231645 is 54613202.

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

It is not a de Polignac number, because 20231645 - 2² = 20231641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20231645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20231641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 288989 + ... + 289058.

It is an arithmetic number, because the mean of its divisors is an integer number (3468288).

Almost surely, 2^20231645 is an apocalyptic number.

It is an amenable number.

20231645 is a deficient number, since it is larger than the sum of its proper divisors (7514659).

20231645 is an equidigital number, since it uses as much as digits as its factorization.

20231645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578059.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20231645 is about 4497.9600931978. The cubic root of 20231645 is about 272.4857103300.

Adding to 20231645 its reverse (54613202), we get a palindrome (74844847).

The spelling of 20231645 in words is "twenty million, two hundred thirty-one thousand, six hundred forty-five".