12021653651605 has 16 divisors (see below), whose sum is σ = 15896970270720. Its totient is φ = 8671074689088.

The previous prime is 12021653651603. The next prime is 12021653651629. The reversal of 12021653651605 is 50615635612021.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 12021653651605 - 2¹ = 12021653651603 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12021653651603) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2150561365 + ... + 2150566954.

It is an arithmetic number, because the mean of its divisors is an integer number (993560641920).

Almost surely, 2^{12021653651605} is an apocalyptic number.

It is an amenable number.

12021653651605 is a deficient number, since it is larger than the sum of its proper divisors (3875316619115).

12021653651605 is a wasteful number, since it uses less digits than its factorization.

12021653651605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4301128380.

The product of its (nonzero) digits is 324000, while the sum is 43.

The spelling of 12021653651605 in words is "twelve trillion, twenty-one billion, six hundred fifty-three million, six hundred fifty-one thousand, six hundred five".