20939139 has 24 divisors (see below), whose sum is σ = 32777472. Its totient is φ = 12804480.

The previous prime is 20939123. The next prime is 20939147. The reversal of 20939139 is 93193902.

It is not a de Polignac number, because 20939139 - 2⁴ = 20939123 is a prime.

It is a super-2 number, since 2×20939139² = 876895084122642, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20939939) 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, 21879 + ... + 22815.

It is an arithmetic number, because the mean of its divisors is an integer number (1365728).

Almost surely, 2^20939139 is an apocalyptic number.

20939139 is a deficient number, since it is larger than the sum of its proper divisors (11838333).

20939139 is a wasteful number, since it uses less digits than its factorization.

20939139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1147 (or 1144 counting only the distinct ones).

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

The square root of 20939139 is about 4575.9303971979. The cubic root of 20939139 is about 275.6256345335.

The spelling of 20939139 in words is "twenty million, nine hundred thirty-nine thousand, one hundred thirty-nine".