21420223040 has 112 divisors (see below), whose sum is σ = 56850076800. Its totient is φ = 7639621632.

The previous prime is 21420223031. The next prime is 21420223067. The reversal of 21420223040 is 4032202412.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 260 + ... + 206979.

Almost surely, 2^21420223040 is an apocalyptic number.

21420223040 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 21420223040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28425038400).

21420223040 is an abundant number, since it is smaller than the sum of its proper divisors (35429853760).

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

21420223040 is a wasteful number, since it uses less digits than its factorization.

21420223040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207292 (or 207282 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21420223040 its reverse (4032202412), we get a palindrome (25452425452).

The spelling of 21420223040 in words is "twenty-one billion, four hundred twenty million, two hundred twenty-three thousand, forty".