21165651212000 has 96 divisors (see below), whose sum is σ = 52005938834304. Its totient is φ = 8465945664000.

The previous prime is 21165651211993. The next prime is 21165651212021. The reversal of 21165651212000 is 21215656112.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128489690 + ... + 128654310.

It is an arithmetic number, because the mean of its divisors is an integer number (541728529524).

Almost surely, 2^{21165651212000} is an apocalyptic number.

21165651212000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21165651212000 is an abundant number, since it is smaller than the sum of its proper divisors (30840287622304).

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

21165651212000 is a wasteful number, since it uses less digits than its factorization.

21165651212000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196789 (or 196771 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

Adding to 21165651212000 its reverse (21215656112), we get a palindrome (21186866868112).

The spelling of 21165651212000 in words is "twenty-one trillion, one hundred sixty-five billion, six hundred fifty-one million, two hundred twelve thousand".