21152343212 has 96 divisors (see below), whose sum is σ = 51304157184. Its totient is φ = 7361798400.

The previous prime is 21152343203. The next prime is 21152343221. The reversal of 21152343212 is 21234325112.

It is an interprime number because it is at equal distance from previous prime (21152343203) and next prime (21152343221).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38918 + ... + 209330.

It is an arithmetic number, because the mean of its divisors is an integer number (534418304).

Almost surely, 2^21152343212 is an apocalyptic number.

21152343212 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 21152343212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25652078592).

21152343212 is an abundant number, since it is smaller than the sum of its proper divisors (30151813972).

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

21152343212 is a wasteful number, since it uses less digits than its factorization.

21152343212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170479 (or 170477 counting only the distinct ones).

The product of its digits is 2880, while the sum is 26.

Adding to 21152343212 its reverse (21234325112), we get a palindrome (42386668324).

The spelling of 21152343212 in words is "twenty-one billion, one hundred fifty-two million, three hundred forty-three thousand, two hundred twelve".