21880643 has 2 divisors, whose sum is σ = 21880644. Its totient is φ = 21880642.

The previous prime is 21880591. The next prime is 21880657. The reversal of 21880643 is 34608812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21880643 - 2¹⁶ = 21815107 is a prime.

It is a super-3 number, since 3×21880643³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21880673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10940321 + 10940322.

It is an arithmetic number, because the mean of its divisors is an integer number (10940322).

Almost surely, 2^21880643 is an apocalyptic number.

21880643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21880643 is an equidigital number, since it uses as much as digits as its factorization.

21880643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 21880643 is about 4677.6749566425. The cubic root of 21880643 is about 279.6962820687.

The spelling of 21880643 in words is "twenty-one million, eight hundred eighty thousand, six hundred forty-three".