21011302120 has 16 divisors (see below), whose sum is σ = 47275429860. Its totient is φ = 8404520832.

The previous prime is 21011302097. The next prime is 21011302121. The reversal of 21011302120 is 2120311012.

It can be written as a sum of positive squares in 2 ways, for example, as 21008183364 + 3118756 = 144942^2 + 1766^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21011302120.

It is not an unprimeable number, because it can be changed into a prime (21011302121) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 262641237 + ... + 262641316.

Almost surely, 2^21011302120 is an apocalyptic number.

21011302120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011302120 is an abundant number, since it is smaller than the sum of its proper divisors (26264127740).

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

21011302120 is a wasteful number, since it uses less digits than its factorization.

21011302120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525282564 (or 525282560 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21011302120 its reverse (2120311012), we get a palindrome (23131613132).

The spelling of 21011302120 in words is "twenty-one billion, eleven million, three hundred two thousand, one hundred twenty".