21471104 has 64 divisors (see below), whose sum is σ = 45239040. Its totient is φ = 10139136.

The previous prime is 21471097. The next prime is 21471133. The reversal of 21471104 is 40117412.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×21471104² = 922016613957632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 258647 + ... + 258729.

It is an arithmetic number, because the mean of its divisors is an integer number (706860).

Almost surely, 2^21471104 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 21471104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22619520).

21471104 is an abundant number, since it is smaller than the sum of its proper divisors (23767936).

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

21471104 is an equidigital number, since it uses as much as digits as its factorization.

21471104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 21471104 is about 4633.6922642748. The cubic root of 21471104 is about 277.9402594056.

Adding to 21471104 its reverse (40117412), we get a palindrome (61588516).

It can be divided in two parts, 2147110 and 4, that multiplied together give a triangular number (8588440 = T₄₁₄₄).

The spelling of 21471104 in words is "twenty-one million, four hundred seventy-one thousand, one hundred four".