21012120000 has 210 divisors, whose sum is σ = 75261508608. Its totient is φ = 5603136000.

The previous prime is 21012119983. The next prime is 21012120047. The reversal of 21012120000 is 2121012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 330817 + ... + 389183.

Almost surely, 2^21012120000 is an apocalyptic number.

21012120000 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 21012120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37630754304).

21012120000 is an abundant number, since it is smaller than the sum of its proper divisors (54249388608).

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

21012120000 is an equidigital number, since it uses as much as digits as its factorization.

21012120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58405 (or 58377 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21012120000 its reverse (2121012), we get a palindrome (21014241012).

The spelling of 21012120000 in words is "twenty-one billion, twelve million, one hundred twenty thousand".