20071685 has 8 divisors (see below), whose sum is σ = 24187416. Its totient is φ = 15989760.

The previous prime is 20071651. The next prime is 20071687. The reversal of 20071685 is 58617002.

It can be written as a sum of positive squares in 4 ways, for example, as 10640644 + 9431041 = 3262^2 + 3071^2 .

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

It is not a de Polignac number, because 20071685 - 2¹⁶ = 20006149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20071687) 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, 7124 + ... + 9533.

It is an arithmetic number, because the mean of its divisors is an integer number (3023427).

Almost surely, 2^20071685 is an apocalyptic number.

It is an amenable number.

20071685 is a deficient number, since it is larger than the sum of its proper divisors (4115731).

20071685 is a wasteful number, since it uses less digits than its factorization.

20071685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16903.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 20071685 is about 4480.1434128831. The cubic root of 20071685 is about 271.7656800105.

Adding to 20071685 its reverse (58617002), we get a palindrome (78688687).

The spelling of 20071685 in words is "twenty million, seventy-one thousand, six hundred eighty-five".