20661323 has 2 divisors, whose sum is σ = 20661324. Its totient is φ = 20661322.

The previous prime is 20661301. The next prime is 20661367. The reversal of 20661323 is 32316602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20661323 is a prime.

It is a super-2 number, since 2×20661323² = 853780536220658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20661373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10330661 + 10330662.

It is an arithmetic number, because the mean of its divisors is an integer number (10330662).

Almost surely, 2^20661323 is an apocalyptic number.

20661323 is a deficient number, since it is larger than the sum of its proper divisors (1).

20661323 is an equidigital number, since it uses as much as digits as its factorization.

20661323 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 20661323 is about 4545.4728026906. The cubic root of 20661323 is about 274.4012228056.

Adding to 20661323 its reverse (32316602), we get a palindrome (52977925).

The spelling of 20661323 in words is "twenty million, six hundred sixty-one thousand, three hundred twenty-three".