21666107203 has 8 divisors (see below), whose sum is σ = 24347197728. Its totient is φ = 19129940544.

The previous prime is 21666107201. The next prime is 21666107251. The reversal of 21666107203 is 30270166612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21666107203 - 2¹ = 21666107201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21666107201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36230650 + ... + 36231247.

It is an arithmetic number, because the mean of its divisors is an integer number (3043399716).

Almost surely, 2^21666107203 is an apocalyptic number.

21666107203 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21666107203 is a deficient number, since it is larger than the sum of its proper divisors (2681090525).

21666107203 is a wasteful number, since it uses less digits than its factorization.

21666107203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72461933.

The product of its (nonzero) digits is 18144, while the sum is 34.

The spelling of 21666107203 in words is "twenty-one billion, six hundred sixty-six million, one hundred seven thousand, two hundred three".