20078139 has 16 divisors (see below), whose sum is σ = 28739232. Its totient is φ = 12423168.

The previous prime is 20078137. The next prime is 20078143. The reversal of 20078139 is 93187002.

It is a happy number.

It is not a de Polignac number, because 20078139 - 2¹ = 20078137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20078131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1027 + ... + 6419.

It is an arithmetic number, because the mean of its divisors is an integer number (1796202).

Almost surely, 2^20078139 is an apocalyptic number.

20078139 is a deficient number, since it is larger than the sum of its proper divisors (8661093).

20078139 is a wasteful number, since it uses less digits than its factorization.

20078139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5486.

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

The square root of 20078139 is about 4480.8636444328. The cubic root of 20078139 is about 271.7948054134.

The spelling of 20078139 in words is "twenty million, seventy-eight thousand, one hundred thirty-nine".