20963881 has 2 divisors, whose sum is σ = 20963882. Its totient is φ = 20963880.

The previous prime is 20963869. The next prime is 20963893. The reversal of 20963881 is 18836902.

It is a balanced prime because it is at equal distance from previous prime (20963869) and next prime (20963893).

It can be written as a sum of positive squares in only one way, i.e., 13213225 + 7750656 = 3635^2 + 2784^2 .

It is a cyclic number.

It is not a de Polignac number, because 20963881 - 2⁵ = 20963849 is a prime.

It is a super-2 number, since 2×20963881² = 878968613164322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20963881.

It is not a weakly prime, because it can be changed into another prime (20963851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10481940 + 10481941.

It is an arithmetic number, because the mean of its divisors is an integer number (10481941).

Almost surely, 2^20963881 is an apocalyptic number.

It is an amenable number.

20963881 is a deficient number, since it is larger than the sum of its proper divisors (1).

20963881 is an equidigital number, since it uses as much as digits as its factorization.

20963881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 20963881 is about 4578.6330929656. The cubic root of 20963881 is about 275.7341529273.

The spelling of 20963881 in words is "twenty million, nine hundred sixty-three thousand, eight hundred eighty-one".