20390139 has 24 divisors (see below), whose sum is σ = 36721152. Its totient is φ = 10591920.

The previous prime is 20390129. The next prime is 20390147. The reversal of 20390139 is 93109302.

It is not a de Polignac number, because 20390139 - 2⁷ = 20390011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20390129) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14019 + ... + 15404.

It is an arithmetic number, because the mean of its divisors is an integer number (1530048).

Almost surely, 2^20390139 is an apocalyptic number.

20390139 is a deficient number, since it is larger than the sum of its proper divisors (16331013).

20390139 is a wasteful number, since it uses less digits than its factorization.

20390139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29447 (or 29444 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 20390139 is about 4515.5441532555. The cubic root of 20390139 is about 273.1954081389.

The spelling of 20390139 in words is "twenty million, three hundred ninety thousand, one hundred thirty-nine".