20718493 has 8 divisors (see below), whose sum is σ = 22273920. Its totient is φ = 19209600.

The previous prime is 20718491. The next prime is 20718497. The reversal of 20718493 is 39481702.

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

It is a cyclic number.

It is not a de Polignac number, because 20718493 - 2¹ = 20718491 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 (20718491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10708 + ... + 12493.

It is an arithmetic number, because the mean of its divisors is an integer number (2784240).

Almost surely, 2^20718493 is an apocalyptic number.

It is an amenable number.

20718493 is a deficient number, since it is larger than the sum of its proper divisors (1555427).

20718493 is a wasteful number, since it uses less digits than its factorization.

20718493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23267.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20718493 is about 4551.7571332399. The cubic root of 20718493 is about 274.6540796525.

The spelling of 20718493 in words is "twenty million, seven hundred eighteen thousand, four hundred ninety-three".