21666203635411 has 32 divisors (see below), whose sum is σ = 22090020986880. Its totient is φ = 21246951194784.

The previous prime is 21666203635381. The next prime is 21666203635471. The reversal of 21666203635411 is 11453630266612.

It is a cyclic number.

It is not a de Polignac number, because 21666203635411 - 2¹⁵ = 21666203602643 is a prime.

It is a super-2 number, since 2×21666203635411² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21666203635471) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13686798726 + ... + 13686800308.

It is an arithmetic number, because the mean of its divisors is an integer number (690313155840).

Almost surely, 2^{21666203635411} is an apocalyptic number.

21666203635411 is a deficient number, since it is larger than the sum of its proper divisors (423817351469).

21666203635411 is a wasteful number, since it uses less digits than its factorization.

21666203635411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3615.

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 21666203635411 in words is "twenty-one trillion, six hundred sixty-six billion, two hundred three million, six hundred thirty-five thousand, four hundred eleven".