21404895 has 16 divisors (see below), whose sum is σ = 34415232. Its totient is φ = 11360160.

The previous prime is 21404869. The next prime is 21404899. The reversal of 21404895 is 59840412.

It is not a de Polignac number, because 21404895 - 2⁵ = 21404863 is a prime.

It is a super-2 number, since 2×21404895² = 916339059922050, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 217 + ... + 6546.

It is an arithmetic number, because the mean of its divisors is an integer number (2150952).

Almost surely, 2^21404895 is an apocalyptic number.

21404895 is a deficient number, since it is larger than the sum of its proper divisors (13010337).

21404895 is a wasteful number, since it uses less digits than its factorization.

21404895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6982.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21404895 is about 4626.5424454986. The cubic root of 21404895 is about 277.6542766843.

The spelling of 21404895 in words is "twenty-one million, four hundred four thousand, eight hundred ninety-five".