21121201101000 has 2048 divisors, whose sum is σ = 91679257313280. Its totient is φ = 3939217920000.

The previous prime is 21121201100999. The next prime is 21121201101041. The reversal of 21121201101000 is 10110212112.

It is a super-2 number, since 2×21121201101000² (a number of 27 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 13444430215 + ... + 13444431785.

It is an arithmetic number, because the mean of its divisors is an integer number (44765262360).

Almost surely, 2^{21121201101000} is an apocalyptic number.

21121201101000 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 21121201101000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45839628656640).

21121201101000 is an abundant number, since it is smaller than the sum of its proper divisors (70558056212280).

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

21121201101000 is a wasteful number, since it uses less digits than its factorization.

21121201101000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1685 (or 1649 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21121201101000 its reverse (10110212112), we get a palindrome (21131311313112).

The spelling of 21121201101000 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred one million, one hundred one thousand".