21084349 has 16 divisors (see below), whose sum is σ = 24905664. Its totient is φ = 17596800.

The previous prime is 21084317. The next prime is 21084377. The reversal of 21084349 is 94348012.

It is not a de Polignac number, because 21084349 - 2⁵ = 21084317 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21084349.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21084379) 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 15 ways as a sum of consecutive naturals, for example, 40209 + ... + 40729.

It is an arithmetic number, because the mean of its divisors is an integer number (1556604).

Almost surely, 2^21084349 is an apocalyptic number.

It is an amenable number.

21084349 is a deficient number, since it is larger than the sum of its proper divisors (3821315).

21084349 is a wasteful number, since it uses less digits than its factorization.

21084349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 21084349 is about 4591.7697024132. The cubic root of 21084349 is about 276.2613090925.

The spelling of 21084349 in words is "twenty-one million, eighty-four thousand, three hundred forty-nine".