21700449 has 12 divisors (see below), whose sum is σ = 33189156. Its totient is φ = 13615872.

The previous prime is 21700409. The next prime is 21700493. The reversal of 21700449 is 94400712.

It is a happy number.

21700449 is a `hidden beast` number, since 217 + 0 + 0 + 449 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18662400 + 3038049 = 4320^2 + 1743^2 .

It is not a de Polignac number, because 21700449 - 2⁷ = 21700321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21700409) 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, 70764 + ... + 71069.

It is an arithmetic number, because the mean of its divisors is an integer number (2765763).

Almost surely, 2^21700449 is an apocalyptic number.

It is an amenable number.

21700449 is a deficient number, since it is larger than the sum of its proper divisors (11488707).

21700449 is a wasteful number, since it uses less digits than its factorization.

21700449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141856 (or 141853 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21700449 is about 4658.3740725708. The cubic root of 21700449 is about 278.9263689768.

The spelling of 21700449 in words is "twenty-one million, seven hundred thousand, four hundred forty-nine".