21965089 has 4 divisors (see below), whose sum is σ = 21984580. Its totient is φ = 21945600.

The previous prime is 21965077. The next prime is 21965101. The reversal of 21965089 is 98056912.

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

It is an interprime number because it is at equal distance from previous prime (21965077) and next prime (21965101).

It can be written as a sum of positive squares in 2 ways, for example, as 10131489 + 11833600 = 3183^2 + 3440^2 .

It is a cyclic number.

It is not a de Polignac number, because 21965089 - 2¹⁹ = 21440801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21965029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7944 + ... + 10345.

It is an arithmetic number, because the mean of its divisors is an integer number (5496145).

Almost surely, 2^21965089 is an apocalyptic number.

It is an amenable number.

21965089 is a deficient number, since it is larger than the sum of its proper divisors (19491).

21965089 is a wasteful number, since it uses less digits than its factorization.

21965089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19490.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 21965089 is about 4686.6927571583. The cubic root of 21965089 is about 280.0556394532.

The spelling of 21965089 in words is "twenty-one million, nine hundred sixty-five thousand, eighty-nine".