20698543 has 4 divisors (see below), whose sum is σ = 21787960. Its totient is φ = 19609128.

The previous prime is 20698529. The next prime is 20698583. The reversal of 20698543 is 34589602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20698543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20698583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 544680 + ... + 544717.

It is an arithmetic number, because the mean of its divisors is an integer number (5446990).

Almost surely, 2^20698543 is an apocalyptic number.

20698543 is a deficient number, since it is larger than the sum of its proper divisors (1089417).

20698543 is a wasteful number, since it uses less digits than its factorization.

20698543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1089416.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 20698543 is about 4549.5651440550. The cubic root of 20698543 is about 274.5658958170.

The spelling of 20698543 in words is "twenty million, six hundred ninety-eight thousand, five hundred forty-three".