21880189 has 4 divisors (see below), whose sum is σ = 21893724. Its totient is φ = 21866656.

The previous prime is 21880171. The next prime is 21880231. The reversal of 21880189 is 98108812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14884164 + 6996025 = 3858^2 + 2645^2 .

It is a cyclic number.

It is not a de Polignac number, because 21880189 - 2²¹ = 19783037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21880169) 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 in 3 ways as a sum of consecutive naturals, for example, 3952 + ... + 7705.

It is an arithmetic number, because the mean of its divisors is an integer number (5473431).

Almost surely, 2^21880189 is an apocalyptic number.

It is an amenable number.

21880189 is a deficient number, since it is larger than the sum of its proper divisors (13535).

21880189 is a wasteful number, since it uses less digits than its factorization.

21880189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13534.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 21880189 is about 4677.6264280081. The cubic root of 21880189 is about 279.6943475889.

The spelling of 21880189 in words is "twenty-one million, eight hundred eighty thousand, one hundred eighty-nine".