21649107 has 32 divisors (see below), whose sum is σ = 31256064. Its totient is φ = 13305600.

The previous prime is 21649097. The next prime is 21649123. The reversal of 21649107 is 70194612.

It is a happy number.

It is not a de Polignac number, because 21649107 - 2⁴ = 21649091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21649207) 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 31 ways as a sum of consecutive naturals, for example, 304882 + ... + 304952.

It is an arithmetic number, because the mean of its divisors is an integer number (976752).

Almost surely, 2^21649107 is an apocalyptic number.

21649107 is a deficient number, since it is larger than the sum of its proper divisors (9606957).

21649107 is a wasteful number, since it uses less digits than its factorization.

21649107 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 21649107 is about 4652.8600881608. The cubic root of 21649107 is about 278.7062207450.

The spelling of 21649107 in words is "twenty-one million, six hundred forty-nine thousand, one hundred seven".