20718049 has 4 divisors (see below), whose sum is σ = 22601520. Its totient is φ = 18834580.

The previous prime is 20718031. The next prime is 20718073. The reversal of 20718049 is 94081702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20718049 - 2⁵ = 20718017 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 20718049.

It is not an unprimeable number, because it can be changed into a prime (20718149) 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, 941719 + ... + 941740.

It is an arithmetic number, because the mean of its divisors is an integer number (5650380).

Almost surely, 2^20718049 is an apocalyptic number.

It is an amenable number.

20718049 is a deficient number, since it is larger than the sum of its proper divisors (1883471).

20718049 is a wasteful number, since it uses less digits than its factorization.

20718049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1883470.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 20718049 is about 4551.7083606048. The cubic root of 20718049 is about 274.6521176809.

The spelling of 20718049 in words is "twenty million, seven hundred eighteen thousand, forty-nine".