20341781 has 6 divisors (see below), whose sum is σ = 20851746. Its totient is φ = 19844000.

The previous prime is 20341777. The next prime is 20341787. The reversal of 20341781 is 18714302.

It can be written as a sum of positive squares in 3 ways, for example, as 902500 + 19439281 = 950^2 + 4409^2 .

It is not a de Polignac number, because 20341781 - 2² = 20341777 is a prime.

It is a super-2 number, since 2×20341781² = 827576108503922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20341781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20341787) 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 5 ways as a sum of consecutive naturals, for example, 4370 + ... + 7731.

It is an arithmetic number, because the mean of its divisors is an integer number (3475291).

Almost surely, 2^20341781 is an apocalyptic number.

It is an amenable number.

20341781 is a deficient number, since it is larger than the sum of its proper divisors (509965).

20341781 is an equidigital number, since it uses as much as digits as its factorization.

20341781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12183 (or 12142 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20341781 is about 4510.1863597860. The cubic root of 20341781 is about 272.9792637669.

The spelling of 20341781 in words is "twenty million, three hundred forty-one thousand, seven hundred eighty-one".