20680357 has 4 divisors (see below), whose sum is σ = 20703276. Its totient is φ = 20657440.

The previous prime is 20680349. The next prime is 20680367. The reversal of 20680357 is 75308602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11249316 + 9431041 = 3354^2 + 3071^2 .

It is a cyclic number.

It is not a de Polignac number, because 20680357 - 2³ = 20680349 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 (20680337) 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, 10048 + ... + 11929.

It is an arithmetic number, because the mean of its divisors is an integer number (5175819).

Almost surely, 2^20680357 is an apocalyptic number.

It is an amenable number.

20680357 is a deficient number, since it is larger than the sum of its proper divisors (22919).

20680357 is an equidigital number, since it uses as much as digits as its factorization.

20680357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22918.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20680357 is about 4547.5660522965. The cubic root of 20680357 is about 274.4854599063.

Adding to 20680357 its reverse (75308602), we get a palindrome (95988959).

The spelling of 20680357 in words is "twenty million, six hundred eighty thousand, three hundred fifty-seven".