20316681 has 48 divisors (see below), whose sum is σ = 38538240. Its totient is φ = 9992160.

The previous prime is 20316677. The next prime is 20316701. The reversal of 20316681 is 18661302.

It is not a de Polignac number, because 20316681 - 2² = 20316677 is a prime.

It is a super-2 number, since 2×20316681² = 825535053711522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20316631) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12396 + ... + 13938.

It is an arithmetic number, because the mean of its divisors is an integer number (802880).

Almost surely, 2^20316681 is an apocalyptic number.

20316681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20316681 is a deficient number, since it is larger than the sum of its proper divisors (18221559).

20316681 is a wasteful number, since it uses less digits than its factorization.

20316681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1586 (or 1583 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20316681 is about 4507.4029107680. The cubic root of 20316681 is about 272.8669399472.

Adding to 20316681 its reverse (18661302), we get a palindrome (38977983).

The spelling of 20316681 in words is "twenty million, three hundred sixteen thousand, six hundred eighty-one".