20947693 has 4 divisors (see below), whose sum is σ = 22559068. Its totient is φ = 19336320.

The previous prime is 20947669. The next prime is 20947727. The reversal of 20947693 is 39674902.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1605289 + 19342404 = 1267^2 + 4398^2 .

It is a cyclic number.

It is not a de Polignac number, because 20947693 - 2²¹ = 18850541 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 (20947613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 805668 + ... + 805693.

It is an arithmetic number, because the mean of its divisors is an integer number (5639767).

Almost surely, 2^20947693 is an apocalyptic number.

It is an amenable number.

20947693 is a deficient number, since it is larger than the sum of its proper divisors (1611375).

20947693 is a wasteful number, since it uses less digits than its factorization.

20947693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1611374.

The product of its (nonzero) digits is 81648, while the sum is 40.

The square root of 20947693 is about 4576.8649750675. The cubic root of 20947693 is about 275.6631620348.

The spelling of 20947693 in words is "twenty million, nine hundred forty-seven thousand, six hundred ninety-three".