20543969 has 2 divisors, whose sum is σ = 20543970. Its totient is φ = 20543968.

The previous prime is 20543953. The next prime is 20544001. The reversal of 20543969 is 96934502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20430400 + 113569 = 4520^2 + 337^2 .

It is a cyclic number.

It is not a de Polignac number, because 20543969 - 2⁴ = 20543953 is a prime.

It is a super-2 number, since 2×20543969² = 844109324545922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20543569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10271984 + 10271985.

It is an arithmetic number, because the mean of its divisors is an integer number (10271985).

Almost surely, 2^20543969 is an apocalyptic number.

It is an amenable number.

20543969 is a deficient number, since it is larger than the sum of its proper divisors (1).

20543969 is an equidigital number, since it uses as much as digits as its factorization.

20543969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 20543969 is about 4532.5455320383. The cubic root of 20543969 is about 273.8807133447.

It can be divided in two parts, 20543 and 969, that added together give a palindrome (21512).

The spelling of 20543969 in words is "twenty million, five hundred forty-three thousand, nine hundred sixty-nine".