21101021000000 has 392 divisors, whose sum is σ = 53091491826456. Its totient is φ = 8320000000000.

The previous prime is 21101020999937. The next prime is 21101021000051. The reversal of 21101021000000 is 12010112.

It can be written as a sum of positive squares in 28 ways, for example, as 19343529904384 + 1757491095616 = 4398128^2 + 1325704^2 .

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 40500999740 + ... + 40501000260.

Almost surely, 2^{21101021000000} is an apocalyptic number.

21101021000000 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 21101021000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26545745913228).

21101021000000 is an abundant number, since it is smaller than the sum of its proper divisors (31990470826456).

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

21101021000000 is an frugal number, since it uses more digits than its factorization.

21101021000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065 (or 1030 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21101021000000 its reverse (12010112), we get a palindrome (21101033010112).

The spelling of 21101021000000 in words is "twenty-one trillion, one hundred one billion, twenty-one million", and thus it is an aban number.