20685129 has 8 divisors (see below), whose sum is σ = 29031840. Its totient is φ = 13064256.

The previous prime is 20685101. The next prime is 20685131. The reversal of 20685129 is 92158602.

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

It is not a de Polignac number, because 20685129 - 2⁷ = 20685001 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20685129.

It is not an unprimeable number, because it can be changed into a prime (20685139) 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, 181392 + ... + 181505.

It is an arithmetic number, because the mean of its divisors is an integer number (3628980).

Almost surely, 2^20685129 is an apocalyptic number.

It is an amenable number.

20685129 is a deficient number, since it is larger than the sum of its proper divisors (8346711).

20685129 is a wasteful number, since it uses less digits than its factorization.

20685129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362919.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 20685129 is about 4548.0906983041. The cubic root of 20685129 is about 274.5065708229.

The spelling of 20685129 in words is "twenty million, six hundred eighty-five thousand, one hundred twenty-nine".