21204111000 has 128 divisors (see below), whose sum is σ = 66743352000. Its totient is φ = 5604300800.

The previous prime is 21204110971. The next prime is 21204111029. The reversal of 21204111000 is 11140212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21204110971) and next prime (21204111029).

It is a super-2 number, since 2×21204111000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 307726 + ... + 370274.

Almost surely, 2^21204111000 is an apocalyptic number.

21204111000 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 21204111000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33371676000).

21204111000 is an abundant number, since it is smaller than the sum of its proper divisors (45539241000).

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

21204111000 is a wasteful number, since it uses less digits than its factorization.

21204111000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62686 (or 62672 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21204111000 its reverse (11140212), we get a palindrome (21215251212).

The spelling of 21204111000 in words is "twenty-one billion, two hundred four million, one hundred eleven thousand".