21406541066 has 8 divisors (see below), whose sum is σ = 33998624100. Its totient is φ = 10073666368.

The previous prime is 21406541063. The next prime is 21406541113. The reversal of 21406541066 is 66014560412.

It can be written as a sum of positive squares in 2 ways, for example, as 21381750625 + 24790441 = 146225^2 + 4979^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21406541063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 314802041 + ... + 314802108.

Almost surely, 2^21406541066 is an apocalyptic number.

21406541066 is a deficient number, since it is larger than the sum of its proper divisors (12592083034).

21406541066 is a wasteful number, since it uses less digits than its factorization.

21406541066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629604168.

The product of its (nonzero) digits is 34560, while the sum is 35.

The spelling of 21406541066 in words is "twenty-one billion, four hundred six million, five hundred forty-one thousand, sixty-six".