21030120012 has 96 divisors (see below), whose sum is σ = 55912550400. Its totient is φ = 6089807680.

The previous prime is 21030119993. The next prime is 21030120031. The reversal of 21030120012 is 21002103012.

It is an interprime number because it is at equal distance from previous prime (21030119993) and next prime (21030120031).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21030120012.

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, 3892489 + ... + 3897887.

It is an arithmetic number, because the mean of its divisors is an integer number (582422400).

Almost surely, 2^21030120012 is an apocalyptic number.

21030120012 is a gapful number since it is divisible by the number (22) 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 21030120012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27956275200).

21030120012 is an abundant number, since it is smaller than the sum of its proper divisors (34882430388).

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

21030120012 is a wasteful number, since it uses less digits than its factorization.

21030120012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6723 (or 6721 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21030120012 its reverse (21002103012), we get a palindrome (42032223024).

The spelling of 21030120012 in words is "twenty-one billion, thirty million, one hundred twenty thousand, twelve".