20870139 has 8 divisors (see below), whose sum is σ = 27858240. Its totient is φ = 13897736.

The previous prime is 20870137. The next prime is 20870149. The reversal of 20870139 is 93107802.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20870139 - 2¹ = 20870137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20870137) 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, 357 + ... + 6470.

It is an arithmetic number, because the mean of its divisors is an integer number (3482280).

Almost surely, 2^20870139 is an apocalyptic number.

20870139 is a deficient number, since it is larger than the sum of its proper divisors (6988101).

20870139 is a wasteful number, since it uses less digits than its factorization.

20870139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7849.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 20870139 is about 4568.3847254801. The cubic root of 20870139 is about 275.3225482561.

The spelling of 20870139 in words is "twenty million, eight hundred seventy thousand, one hundred thirty-nine".