20685634 has 8 divisors (see below), whose sum is σ = 32853708. Its totient is φ = 9734400.

The previous prime is 20685631. The next prime is 20685653. The reversal of 20685634 is 43658602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15233409 + 5452225 = 3903^2 + 2335^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (34), and also a Moran number because the ratio is a prime number: 608401 = 20685634 / (2 + 0 + 6 + 8 + 5 + 6 + 3 + 4).

It is a self number, because there is not a number n which added to its sum of digits gives 20685634.

It is not an unprimeable number, because it can be changed into a prime (20685631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 304167 + ... + 304234.

Almost surely, 2^20685634 is an apocalyptic number.

20685634 is a deficient number, since it is larger than the sum of its proper divisors (12168074).

20685634 is a wasteful number, since it uses less digits than its factorization.

20685634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608420.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 20685634 is about 4548.1462157675. The cubic root of 20685634 is about 274.5088047094.

It can be divided in two parts, 206856 and 34, that multiplied together give a square (7033104 = 2652²).

The spelling of 20685634 in words is "twenty million, six hundred eighty-five thousand, six hundred thirty-four".