21221365123305 has 24 divisors (see below), whose sum is σ = 36784702543680. Its totient is φ = 11317752784800.

The previous prime is 21221365123237. The next prime is 21221365123307. The reversal of 21221365123305 is 50332156312212.

21221365123305 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 136 + 512 + 3 + 3 + 0 + 5 = 666.

It is not a de Polignac number, because 21221365123305 - 2³⁰ = 21220291381481 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221365123305.

It is not an unprimeable number, because it can be changed into a prime (21221365123307) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4756021 + ... + 8066130.

It is an arithmetic number, because the mean of its divisors is an integer number (1532695939320).

Almost surely, 2^{21221365123305} is an apocalyptic number.

It is an amenable number.

21221365123305 is a deficient number, since it is larger than the sum of its proper divisors (15563337420375).

21221365123305 is a wasteful number, since it uses less digits than its factorization.

21221365123305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12858941 (or 12858938 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 21221365123305 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred sixty-five million, one hundred twenty-three thousand, three hundred five".