21212333040 has 160 divisors (see below), whose sum is σ = 68652302400. Its totient is φ = 5411266560.

The previous prime is 21212332997. The next prime is 21212333041. The reversal of 21212333040 is 4033321212.

It is a junction number, because it is equal to n+sod(n) for n = 21212332998 and 21212333016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212333041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 744660 + ... + 772620.

It is an arithmetic number, because the mean of its divisors is an integer number (429076890).

Almost surely, 2^21212333040 is an apocalyptic number.

21212333040 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 21212333040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34326151200).

21212333040 is an abundant number, since it is smaller than the sum of its proper divisors (47439969360).

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

21212333040 is a wasteful number, since it uses less digits than its factorization.

21212333040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28115 (or 28109 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21212333040 its reverse (4033321212), we get a palindrome (25245654252).

The spelling of 21212333040 in words is "twenty-one billion, two hundred twelve million, three hundred thirty-three thousand, forty".