21451089 has 16 divisors (see below), whose sum is σ = 31509504. Its totient is φ = 12872400.

The previous prime is 21451081. The next prime is 21451099. The reversal of 21451089 is 98015412.

It is a happy number.

It is not a de Polignac number, because 21451089 - 2³ = 21451081 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21451081) 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 15 ways as a sum of consecutive naturals, for example, 244 + ... + 6554.

It is an arithmetic number, because the mean of its divisors is an integer number (1969344).

Almost surely, 2^21451089 is an apocalyptic number.

It is an amenable number.

21451089 is a deficient number, since it is larger than the sum of its proper divisors (10058415).

21451089 is a wasteful number, since it uses less digits than its factorization.

21451089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6428.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 21451089 is about 4631.5320359466. The cubic root of 21451089 is about 277.8538688198.

The spelling of 21451089 in words is "twenty-one million, four hundred fifty-one thousand, eighty-nine".