21134420 has 12 divisors (see below), whose sum is σ = 44382324. Its totient is φ = 8453760.

The previous prime is 21134419. The next prime is 21134431. The reversal of 21134420 is 2443112.

It can be written as a sum of positive squares in 2 ways, for example, as 8375236 + 12759184 = 2894^2 + 3572^2 .

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 528341 + ... + 528380.

It is an arithmetic number, because the mean of its divisors is an integer number (3698527).

Almost surely, 2^21134420 is an apocalyptic number.

21134420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21134420 is an abundant number, since it is smaller than the sum of its proper divisors (23247904).

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

21134420 is a wasteful number, since it uses less digits than its factorization.

21134420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056730 (or 1056728 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21134420 is about 4597.2187244028. The cubic root of 21134420 is about 276.4798241706.

Adding to 21134420 its reverse (2443112), we get a palindrome (23577532).

The spelling of 21134420 in words is "twenty-one million, one hundred thirty-four thousand, four hundred twenty".