21106272 has 144 divisors (see below), whose sum is σ = 64350720. Its totient is φ = 6040320.

The previous prime is 21106259. The next prime is 21106277. The reversal of 21106272 is 27260112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21106277) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 267129 + ... + 267207.

It is an arithmetic number, because the mean of its divisors is an integer number (446880).

Almost surely, 2^21106272 is an apocalyptic number.

21106272 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21106272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32175360).

21106272 is an abundant number, since it is smaller than the sum of its proper divisors (43244448).

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

21106272 is a wasteful number, since it uses less digits than its factorization.

21106272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 21106272 is about 4594.1562881556. The cubic root of 21106272 is about 276.3570258849.

Adding to 21106272 its reverse (27260112), we get a palindrome (48366384).

The spelling of 21106272 in words is "twenty-one million, one hundred six thousand, two hundred seventy-two".