21986141 has 2 divisors, whose sum is σ = 21986142. Its totient is φ = 21986140.

The previous prime is 21986131. The next prime is 21986143. The reversal of 21986141 is 14168912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21808900 + 177241 = 4670^2 + 421^2 .

It is a cyclic number.

It is not a de Polignac number, because 21986141 - 2⁶ = 21986077 is a prime.

It is a Sophie Germain prime.

Together with 21986143, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p_1388435 and since 21986141 and 1388435 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 21986098 and 21986107.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21986143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10993070 + 10993071.

It is an arithmetic number, because the mean of its divisors is an integer number (10993071).

Almost surely, 2^21986141 is an apocalyptic number.

It is an amenable number.

21986141 is a deficient number, since it is larger than the sum of its proper divisors (1).

21986141 is an equidigital number, since it uses as much as digits as its factorization.

21986141 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 32.

The square root of 21986141 is about 4688.9381527165. The cubic root of 21986141 is about 280.1450821256.

The spelling of 21986141 in words is "twenty-one million, nine hundred eighty-six thousand, one hundred forty-one".