20139993 has 12 divisors (see below), whose sum is σ = 29151408. Its totient is φ = 13398840.

The previous prime is 20139991. The next prime is 20139997. The reversal of 20139993 is 39993102.

It is not a de Polignac number, because 20139993 - 2¹ = 20139991 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (20139991) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2878 + ... + 6968.

It is an arithmetic number, because the mean of its divisors is an integer number (2429284).

Almost surely, 2^20139993 is an apocalyptic number.

It is an amenable number.

20139993 is a deficient number, since it is larger than the sum of its proper divisors (9011415).

20139993 is a wasteful number, since it uses less digits than its factorization.

20139993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4644 (or 4641 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 20139993 is about 4487.7603545644. The cubic root of 20139993 is about 272.0736221197.

The spelling of 20139993 in words is "twenty million, one hundred thirty-nine thousand, nine hundred ninety-three".