20818693 has 24 divisors (see below), whose sum is σ = 25994304. Its totient is φ = 16320000.

The previous prime is 20818649. The next prime is 20818739. The reversal of 20818693 is 39681802.

It is not a de Polignac number, because 20818693 - 2⁹ = 20818181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20818643) 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 23 ways as a sum of consecutive naturals, for example, 82818 + ... + 83068.

It is an arithmetic number, because the mean of its divisors is an integer number (1083096).

Almost surely, 2^20818693 is an apocalyptic number.

It is an amenable number.

20818693 is a deficient number, since it is larger than the sum of its proper divisors (5175611).

20818693 is a wasteful number, since it uses less digits than its factorization.

20818693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 20818693 is about 4562.7505958577. The cubic root of 20818693 is about 275.0961338829.

The spelling of 20818693 in words is "twenty million, eight hundred eighteen thousand, six hundred ninety-three".