21456099 has 12 divisors (see below), whose sum is σ = 35419696. Its totient is φ = 12260592.

The previous prime is 21456089. The next prime is 21456103. The reversal of 21456099 is 99065412.

21456099 is a `hidden beast` number, since 2 + 1 + 4 + 560 + 99 = 666.

It is not a de Polignac number, because 21456099 - 2⁵ = 21456067 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (21456049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170224 + ... + 170349.

Almost surely, 2^21456099 is an apocalyptic number.

21456099 is a deficient number, since it is larger than the sum of its proper divisors (13963597).

21456099 is a wasteful number, since it uses less digits than its factorization.

21456099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340586 (or 340583 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 21456099 is about 4632.0728621212. The cubic root of 21456099 is about 277.8754984835.

The spelling of 21456099 in words is "twenty-one million, four hundred fifty-six thousand, ninety-nine".