21682589 has 2 divisors, whose sum is σ = 21682590. Its totient is φ = 21682588.

The previous prime is 21682519. The next prime is 21682613. The reversal of 21682589 is 98528612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15077689 + 6604900 = 3883^2 + 2570^2 .

It is a cyclic number.

It is not a de Polignac number, because 21682589 - 2¹⁶ = 21617053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21682519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10841294 + 10841295.

It is an arithmetic number, because the mean of its divisors is an integer number (10841295).

Almost surely, 2^21682589 is an apocalyptic number.

It is an amenable number.

21682589 is a deficient number, since it is larger than the sum of its proper divisors (1).

21682589 is an equidigital number, since it uses as much as digits as its factorization.

21682589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69120, while the sum is 41.

The square root of 21682589 is about 4656.4567001101. The cubic root of 21682589 is about 278.8498269010.

The spelling of 21682589 in words is "twenty-one million, six hundred eighty-two thousand, five hundred eighty-nine".