20645251500443 has 16 divisors (see below), whose sum is σ = 21928910610432. Its totient is φ = 19404568008000.

The previous prime is 20645251500413. The next prime is 20645251500473. The reversal of 20645251500443 is 34400515254602.

It is an interprime number because it is at equal distance from previous prime (20645251500413) and next prime (20645251500473).

It is a cyclic number.

It is not a de Polignac number, because 20645251500443 - 2²⁰ = 20645250451867 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

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 20645251500443.

It is not an unprimeable number, because it can be changed into a prime (20645251500413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36136553 + ... + 36703418.

It is an arithmetic number, because the mean of its divisors is an integer number (1370556913152).

Almost surely, 2^{20645251500443} is an apocalyptic number.

20645251500443 is a deficient number, since it is larger than the sum of its proper divisors (1283659109989).

20645251500443 is a wasteful number, since it uses less digits than its factorization.

20645251500443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72840266.

The product of its (nonzero) digits is 576000, while the sum is 41.

The spelling of 20645251500443 in words is "twenty trillion, six hundred forty-five billion, two hundred fifty-one million, five hundred thousand, four hundred forty-three".