20685529 has 8 divisors (see below), whose sum is σ = 21166920. Its totient is φ = 20207616.

The previous prime is 20685523. The next prime is 20685551. The reversal of 20685529 is 92558602.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1225 + 20684304 = 35^2 + 4548^2 .

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 20685529 - 2¹³ = 20677337 is a prime.

It is a super-2 number, since 2×20685529² = 855782220019682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20685523) 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, 13977 + ... + 15385.

It is an arithmetic number, because the mean of its divisors is an integer number (2645865).

Almost surely, 2^20685529 is an apocalyptic number.

It is an amenable number.

20685529 is a deficient number, since it is larger than the sum of its proper divisors (481391).

20685529 is a wasteful number, since it uses less digits than its factorization.

20685529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 20685529 is about 4548.1346725883. The cubic root of 20685529 is about 274.5083402409.

The spelling of 20685529 in words is "twenty million, six hundred eighty-five thousand, five hundred twenty-nine".