21881359 has 2 divisors, whose sum is σ = 21881360. Its totient is φ = 21881358.

The previous prime is 21881351. The next prime is 21881383. The reversal of 21881359 is 95318812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21881359 - 2³ = 21881351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21881351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10940679 + 10940680.

It is an arithmetic number, because the mean of its divisors is an integer number (10940680).

Almost surely, 2^21881359 is an apocalyptic number.

21881359 is a deficient number, since it is larger than the sum of its proper divisors (1).

21881359 is an equidigital number, since it uses as much as digits as its factorization.

21881359 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 37.

The square root of 21881359 is about 4677.7514897651. The cubic root of 21881359 is about 279.6993328681.

The spelling of 21881359 in words is "twenty-one million, eight hundred eighty-one thousand, three hundred fifty-nine".