21279104 has 128 divisors (see below), whose sum is σ = 56401920. Its totient is φ = 7741440.

The previous prime is 21279101. The next prime is 21279131. The reversal of 21279104 is 40197212.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21279101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167489 + ... + 167615.

It is an arithmetic number, because the mean of its divisors is an integer number (440640).

Almost surely, 2^21279104 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 21279104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28200960).

21279104 is an abundant number, since it is smaller than the sum of its proper divisors (35122816).

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

21279104 is a wasteful number, since it uses less digits than its factorization.

21279104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21279104 is about 4612.9279205294. The cubic root of 21279104 is about 277.1093070846.

The spelling of 21279104 in words is "twenty-one million, two hundred seventy-nine thousand, one hundred four".