21212109999960 has 128 divisors (see below), whose sum is σ = 71035903445760. Its totient is φ = 5022740620800.

The previous prime is 21212109999947. The next prime is 21212109999991. The reversal of 21212109999960 is 6999990121212.

It is a super-3 number, since 3×21212109999960³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a junction number, because it is equal to n+sod(n) for n = 21212109999894 and 21212109999903.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186801151 + ... + 186914670.

It is an arithmetic number, because the mean of its divisors is an integer number (554967995670).

Almost surely, 2^{21212109999960} is an apocalyptic number.

21212109999960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212109999960 is an abundant number, since it is smaller than the sum of its proper divisors (49823793445800).

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

21212109999960 is a wasteful number, since it uses less digits than its factorization.

21212109999960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373715889 (or 373715885 counting only the distinct ones).

The product of its (nonzero) digits is 2834352, while the sum is 60.

The spelling of 21212109999960 in words is "twenty-one trillion, two hundred twelve billion, one hundred nine million, nine hundred ninety-nine thousand, nine hundred sixty".