21408995 has 4 divisors (see below), whose sum is σ = 25690800. Its totient is φ = 17127192.

The previous prime is 21408983. The next prime is 21409009. The reversal of 21408995 is 59980412.

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

It is a cyclic number.

It is not a de Polignac number, because 21408995 - 2¹² = 21404899 is a prime.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2140895 + ... + 2140904.

It is an arithmetic number, because the mean of its divisors is an integer number (6422700).

Almost surely, 2^21408995 is an apocalyptic number.

21408995 is a deficient number, since it is larger than the sum of its proper divisors (4281805).

21408995 is an equidigital number, since it uses as much as digits as its factorization.

21408995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4281804.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 21408995 is about 4626.9855197526. The cubic root of 21408995 is about 277.6720033126.

The spelling of 21408995 in words is "twenty-one million, four hundred eight thousand, nine hundred ninety-five".