20993117 has 4 divisors (see below), whose sum is σ = 21085020. Its totient is φ = 20901216.

The previous prime is 20993111. The next prime is 20993123. The reversal of 20993117 is 71139902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71139902 = 2 ⋅35569951.

It is an interprime number because it is at equal distance from previous prime (20993111) and next prime (20993123).

It can be written as a sum of positive squares in 2 ways, for example, as 14546596 + 6446521 = 3814^2 + 2539^2 .

It is a cyclic number.

It is not a de Polignac number, because 20993117 - 2¹⁶ = 20927581 is a prime.

It is a super-2 number, since 2×20993117² = 881421922751378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20993111) 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, 45608 + ... + 46065.

It is an arithmetic number, because the mean of its divisors is an integer number (5271255).

Almost surely, 2^20993117 is an apocalyptic number.

It is an amenable number.

20993117 is a deficient number, since it is larger than the sum of its proper divisors (91903).

20993117 is an equidigital number, since it uses as much as digits as its factorization.

20993117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91902.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 20993117 is about 4581.8246365395. The cubic root of 20993117 is about 275.8622720029.

The spelling of 20993117 in words is "twenty million, nine hundred ninety-three thousand, one hundred seventeen".