21134256 has 80 divisors (see below), whose sum is σ = 64162560. Its totient is φ = 5909760.

The previous prime is 21134249. The next prime is 21134273. The reversal of 21134256 is 65243112.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5325 + ... + 8403.

It is an arithmetic number, because the mean of its divisors is an integer number (802032).

Almost surely, 2^21134256 is an apocalyptic number.

21134256 is a gapful number since it is divisible by the number (26) 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 21134256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32081280).

21134256 is an abundant number, since it is smaller than the sum of its proper divisors (43028304).

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

21134256 is a wasteful number, since it uses less digits than its factorization.

21134256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3114 (or 3108 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 21134256 is about 4597.2008874967. The cubic root of 21134256 is about 276.4791090212.

Adding to 21134256 its reverse (65243112), we get a palindrome (86377368).

The spelling of 21134256 in words is "twenty-one million, one hundred thirty-four thousand, two hundred fifty-six".