20820685 has 8 divisors (see below), whose sum is σ = 25790976. Its totient is φ = 16119120.

The previous prime is 20820649. The next prime is 20820689. The reversal of 20820685 is 58602802.

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

It is not a de Polignac number, because 20820685 - 2¹⁵ = 20787917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820689) 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, 67009 + ... + 67318.

It is an arithmetic number, because the mean of its divisors is an integer number (3223872).

Almost surely, 2^20820685 is an apocalyptic number.

It is an amenable number.

20820685 is a deficient number, since it is larger than the sum of its proper divisors (4970291).

20820685 is a wasteful number, since it uses less digits than its factorization.

20820685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134363.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 20820685 is about 4562.9688800166. The cubic root of 20820685 is about 275.1049076329.

The spelling of 20820685 in words is "twenty million, eight hundred twenty thousand, six hundred eighty-five".