20799681 has 16 divisors (see below), whose sum is σ = 32169984. Its totient is φ = 11707344.

The previous prime is 20799631. The next prime is 20799689. The reversal of 20799681 is 18699702.

It is not a de Polignac number, because 20799681 - 2⁹ = 20799169 is a prime.

It is a super-2 number, since 2×20799681² = 865253459403522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20799689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5985 + ... + 8798.

It is an arithmetic number, because the mean of its divisors is an integer number (2010624).

Almost surely, 2^20799681 is an apocalyptic number.

20799681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20799681 is a deficient number, since it is larger than the sum of its proper divisors (11370303).

20799681 is a wasteful number, since it uses less digits than its factorization.

20799681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14860.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 20799681 is about 4560.6667275739. Note that the first 3 decimals coincide. The cubic root of 20799681 is about 275.0123674879.

The spelling of 20799681 in words is "twenty million, seven hundred ninety-nine thousand, six hundred eighty-one".