20393999 has 8 divisors (see below), whose sum is σ = 21960720. Its totient is φ = 18868096.

The previous prime is 20393983. The next prime is 20394037. The reversal of 20393999 is 99939302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20393999 - 2⁴ = 20393983 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 (20393299) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9164 + ... + 11169.

It is an arithmetic number, because the mean of its divisors is an integer number (2745090).

Almost surely, 2^20393999 is an apocalyptic number.

20393999 is a deficient number, since it is larger than the sum of its proper divisors (1566721).

20393999 is a wasteful number, since it uses less digits than its factorization.

20393999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20409.

The product of its (nonzero) digits is 118098, while the sum is 44.

The square root of 20393999 is about 4515.9715455259. The cubic root of 20393999 is about 273.2126463366.

The spelling of 20393999 in words is "twenty million, three hundred ninety-three thousand, nine hundred ninety-nine".