21424100 has 36 divisors (see below), whose sum is σ = 47996928. Its totient is φ = 8292000.

The previous prime is 21424093. The next prime is 21424129. The reversal of 21424100 is 142412.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 356 + ... + 6555.

It is an arithmetic number, because the mean of its divisors is an integer number (1333248).

Almost surely, 2^21424100 is an apocalyptic number.

21424100 is a gapful number since it is divisible by the number (20) 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 21424100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23998464).

21424100 is an abundant number, since it is smaller than the sum of its proper divisors (26572828).

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

21424100 is a wasteful number, since it uses less digits than its factorization.

21424100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6956 (or 6949 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 21424100 is about 4628.6175041798. The cubic root of 21424100 is about 277.7372912845.

Adding to 21424100 its reverse (142412), we get a palindrome (21566512).

The spelling of 21424100 in words is "twenty-one million, four hundred twenty-four thousand, one hundred".