20685105 has 96 divisors (see below), whose sum is σ = 44323200. Its totient is φ = 9120384.

The previous prime is 20685101. The next prime is 20685131. The reversal of 20685105 is 50158602.

It is not a de Polignac number, because 20685105 - 2² = 20685101 is a prime.

It is a super-2 number, since 2×20685105² = 855747137722050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20685101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 350566 + ... + 350624.

It is an arithmetic number, because the mean of its divisors is an integer number (461700).

Almost surely, 2^20685105 is an apocalyptic number.

It is an amenable number.

20685105 is an abundant number, since it is smaller than the sum of its proper divisors (23638095).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20685105 is a wasteful number, since it uses less digits than its factorization.

20685105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 20685105 is about 4548.0880598335. The cubic root of 20685105 is about 274.5064646571.

The spelling of 20685105 in words is "twenty million, six hundred eighty-five thousand, one hundred five".