20417993 has 4 divisors (see below), whose sum is σ = 20532240. Its totient is φ = 20303748.

The previous prime is 20417987. The next prime is 20418011. The reversal of 20417993 is 39971402.

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 a cyclic number.

It is not a de Polignac number, because 20417993 - 2⁴ = 20417977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20417923) 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, 56855 + ... + 57212.

It is an arithmetic number, because the mean of its divisors is an integer number (5133060).

Almost surely, 2^20417993 is an apocalyptic number.

It is an amenable number.

20417993 is a deficient number, since it is larger than the sum of its proper divisors (114247).

20417993 is a wasteful number, since it uses less digits than its factorization.

20417993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114246.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20417993 is about 4518.6273358178. The cubic root of 20417993 is about 273.3197512915.

The spelling of 20417993 in words is "twenty million, four hundred seventeen thousand, nine hundred ninety-three".