20296781 has 8 divisors (see below), whose sum is σ = 21192600. Its totient is φ = 19414080.

The previous prime is 20296777. The next prime is 20296789. The reversal of 20296781 is 18769202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2941225 + 17355556 = 1715^2 + 4166^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20296781 - 2² = 20296777 is a prime.

It is a super-2 number, since 2×20296781² = 823918637923922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20296789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50 + ... + 6371.

It is an arithmetic number, because the mean of its divisors is an integer number (2649075).

Almost surely, 2^20296781 is an apocalyptic number.

It is an amenable number.

20296781 is a deficient number, since it is larger than the sum of its proper divisors (895819).

20296781 is a wasteful number, since it uses less digits than its factorization.

20296781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6559.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 20296781 is about 4505.1948903460. The cubic root of 20296781 is about 272.7778206341. Note that the first 3 decimals are identical.

The spelling of 20296781 in words is "twenty million, two hundred ninety-six thousand, seven hundred eighty-one".