21666345132403 has 16 divisors (see below), whose sum is σ = 22850726169600. Its totient is φ = 20486388883680.

The previous prime is 21666345132401. The next prime is 21666345132449. The reversal of 21666345132403 is 30423154366612.

It is a cyclic number.

It is not a de Polignac number, because 21666345132403 - 2¹ = 21666345132401 is a prime.

It is a super-2 number, since 2×21666345132403² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21666345132401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38845368 + ... + 39399178.

It is an arithmetic number, because the mean of its divisors is an integer number (1428170385600).

Almost surely, 2^{21666345132403} is an apocalyptic number.

21666345132403 is a deficient number, since it is larger than the sum of its proper divisors (1184381037197).

21666345132403 is a wasteful number, since it uses less digits than its factorization.

21666345132403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557802.

The product of its (nonzero) digits is 1866240, while the sum is 46.

The spelling of 21666345132403 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred forty-five million, one hundred thirty-two thousand, four hundred three".