20881697 has 2 divisors, whose sum is σ = 20881698. Its totient is φ = 20881696.

The previous prime is 20881687. The next prime is 20881699. The reversal of 20881697 is 79618802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16654561 + 4227136 = 4081^2 + 2056^2 .

It is a cyclic number.

It is not a de Polignac number, because 20881697 - 2⁶ = 20881633 is a prime.

Together with 20881699, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20881699) 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 as a sum of consecutive naturals, namely, 10440848 + 10440849.

It is an arithmetic number, because the mean of its divisors is an integer number (10440849).

Almost surely, 2^20881697 is an apocalyptic number.

It is an amenable number.

20881697 is a deficient number, since it is larger than the sum of its proper divisors (1).

20881697 is an equidigital number, since it uses as much as digits as its factorization.

20881697 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 20881697 is about 4569.6495489260. The cubic root of 20881697 is about 275.3733639336.

The spelling of 20881697 in words is "twenty million, eight hundred eighty-one thousand, six hundred ninety-seven".