21649116 has 12 divisors (see below), whose sum is σ = 50514632. Its totient is φ = 7216368.

The previous prime is 21649097. The next prime is 21649123. The reversal of 21649116 is 61194612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 902035 + ... + 902058.

Almost surely, 2^21649116 is an apocalyptic number.

It is an amenable number.

21649116 is an abundant number, since it is smaller than the sum of its proper divisors (28865516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21649116 is a wasteful number, since it uses less digits than its factorization.

21649116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1804100 (or 1804098 counting only the distinct ones).

The product of its digits is 2592, while the sum is 30.

The square root of 21649116 is about 4652.8610553078. The cubic root of 21649116 is about 278.7062593663.

The spelling of 21649116 in words is "twenty-one million, six hundred forty-nine thousand, one hundred sixteen".