21420014220 has 480 divisors, whose sum is σ = 76583707200. Its totient is φ = 4964198400.

The previous prime is 21420014219. The next prime is 21420014221. The reversal of 21420014220 is 2241002412.

21420014220 is a `hidden beast` number, since 21 + 420 + 0 + 1 + 4 + 220 = 666.

It is an interprime number because it is at equal distance from previous prime (21420014219) and next prime (21420014221).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21420014193 and 21420014202.

It is not an unprimeable number, because it can be changed into a prime (21420014221) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 93537066 + ... + 93537294.

It is an arithmetic number, because the mean of its divisors is an integer number (159549390).

Almost surely, 2^21420014220 is an apocalyptic number.

21420014220 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 21420014220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38291853600).

21420014220 is an abundant number, since it is smaller than the sum of its proper divisors (55163692980).

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

21420014220 is a wasteful number, since it uses less digits than its factorization.

21420014220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21420014220 its reverse (2241002412), we get a palindrome (23661016632).

The spelling of 21420014220 in words is "twenty-one billion, four hundred twenty million, fourteen thousand, two hundred twenty".