20690139 has 8 divisors (see below), whose sum is σ = 29209680. Its totient is φ = 12982016.

The previous prime is 20690099. The next prime is 20690143. The reversal of 20690139 is 93109602.

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

It is not a de Polignac number, because 20690139 - 2⁸ = 20689883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20690149) 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, 202794 + ... + 202895.

It is an arithmetic number, because the mean of its divisors is an integer number (3651210).

Almost surely, 2^20690139 is an apocalyptic number.

20690139 is a deficient number, since it is larger than the sum of its proper divisors (8519541).

20690139 is a wasteful number, since it uses less digits than its factorization.

20690139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405709.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 20690139 is about 4548.6414455307. The cubic root of 20690139 is about 274.5287311376.

The spelling of 20690139 in words is "twenty million, six hundred ninety thousand, one hundred thirty-nine".