21416164 has 48 divisors (see below), whose sum is σ = 48254976. Its totient is φ = 8071200.

The previous prime is 21416117. The next prime is 21416167. The reversal of 21416164 is 46161412.

21416164 = T₇₀₇ + T₇₀₈ + ... + T₇₈₃.

It is not an unprimeable number, because it can be changed into a prime (21416167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8427 + ... + 10669.

It is an arithmetic number, because the mean of its divisors is an integer number (1005312).

Almost surely, 2^21416164 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21416164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24127488).

21416164 is an abundant number, since it is smaller than the sum of its proper divisors (26838812).

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

21416164 is a wasteful number, since it uses less digits than its factorization.

21416164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296 (or 2294 counting only the distinct ones).

The product of its digits is 1152, while the sum is 25.

The square root of 21416164 is about 4627.7601493595. The cubic root of 21416164 is about 277.7029935333.

Adding to 21416164 its reverse (46161412), we get a palindrome (67577576).

The spelling of 21416164 in words is "twenty-one million, four hundred sixteen thousand, one hundred sixty-four".