21413220 has 24 divisors (see below), whose sum is σ = 59957184. Its totient is φ = 5710176.

The previous prime is 21413191. The next prime is 21413221. The reversal of 21413220 is 2231412.

21413220 = T₃₉₅ + T₃₉₆ + ... + T₅₇₄.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21413220.

It is not an unprimeable number, because it can be changed into a prime (21413221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178384 + ... + 178503.

It is an arithmetic number, because the mean of its divisors is an integer number (2498216).

Almost surely, 2^21413220 is an apocalyptic number.

21413220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21413220 is an abundant number, since it is smaller than the sum of its proper divisors (38543964).

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

21413220 is a wasteful number, since it uses less digits than its factorization.

21413220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356899 (or 356897 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21413220 is about 4627.4420579841. The cubic root of 21413220 is about 277.6902680194.

Adding to 21413220 its reverse (2231412), we get a palindrome (23644632).

The spelling of 21413220 in words is "twenty-one million, four hundred thirteen thousand, two hundred twenty".