20643693 has 16 divisors (see below), whose sum is σ = 31771776. Its totient is φ = 11678400.

The previous prime is 20643683. The next prime is 20643697. The reversal of 20643693 is 39634602.

It is not a de Polignac number, because 20643693 - 2¹⁸ = 20381549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643697) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2746 + ... + 6987.

It is an arithmetic number, because the mean of its divisors is an integer number (1985736).

Almost surely, 2^20643693 is an apocalyptic number.

It is an amenable number.

20643693 is a deficient number, since it is larger than the sum of its proper divisors (11128083).

20643693 is a wasteful number, since it uses less digits than its factorization.

20643693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9844.

The product of its (nonzero) digits is 23328, while the sum is 33.

The square root of 20643693 is about 4543.5330966111. The cubic root of 20643693 is about 274.3231531004.

The spelling of 20643693 in words is "twenty million, six hundred forty-three thousand, six hundred ninety-three".