20217693 has 4 divisors (see below), whose sum is σ = 26956928. Its totient is φ = 13478460.

The previous prime is 20217679. The next prime is 20217733. The reversal of 20217693 is 39671202.

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 not a de Polignac number, because 20217693 - 2⁴ = 20217677 is a prime.

It is a super-2 number, since 2×20217693² = 817510220484498, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20217693.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20217193) 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, 3369613 + ... + 3369618.

It is an arithmetic number, because the mean of its divisors is an integer number (6739232).

Almost surely, 2^20217693 is an apocalyptic number.

It is an amenable number.

20217693 is a deficient number, since it is larger than the sum of its proper divisors (6739235).

20217693 is an equidigital number, since it uses as much as digits as its factorization.

20217693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6739234.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 20217693 is about 4496.4089004449. The cubic root of 20217693 is about 272.4230593877.

Adding to 20217693 its reverse (39671202), we get a palindrome (59888895).

It can be divided in two parts, 20217 and 693, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20217693 in words is "twenty million, two hundred seventeen thousand, six hundred ninety-three".