21220201000 has 64 divisors (see below), whose sum is σ = 50147145360. Its totient is φ = 8404000000.

The previous prime is 21220200931. The next prime is 21220201031. The reversal of 21220201000 is 10202212.

It can be written as a sum of positive squares in 8 ways, for example, as 1290102724 + 19930098276 = 35918^2 + 141174^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

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, 4051 + ... + 206050.

Almost surely, 2^21220201000 is an apocalyptic number.

21220201000 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 21220201000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25073572680).

21220201000 is an abundant number, since it is smaller than the sum of its proper divisors (28926944360).

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

21220201000 is a wasteful number, since it uses less digits than its factorization.

21220201000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210223 (or 210209 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21220201000 its reverse (10202212), we get a palindrome (21230403212).

The spelling of 21220201000 in words is "twenty-one billion, two hundred twenty million, two hundred one thousand".