21005540522213 has 64 divisors (see below), whose sum is σ = 24958654156800. Its totient is φ = 17491861094400.

The previous prime is 21005540522209. The next prime is 21005540522249. The reversal of 21005540522213 is 31222504550012.

It is a cyclic number.

It is not a de Polignac number, because 21005540522213 - 2² = 21005540522209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21005540522213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005540522513) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3414976688 + ... + 3414982838.

It is an arithmetic number, because the mean of its divisors is an integer number (389978971200).

Almost surely, 2^{21005540522213} is an apocalyptic number.

21005540522213 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21005540522213 is a deficient number, since it is larger than the sum of its proper divisors (3953113634587).

21005540522213 is a wasteful number, since it uses less digits than its factorization.

21005540522213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8802.

The product of its (nonzero) digits is 24000, while the sum is 32.

The spelling of 21005540522213 in words is "twenty-one trillion, five billion, five hundred forty million, five hundred twenty-two thousand, two hundred thirteen".