21756663106 has 8 divisors (see below), whose sum is σ = 32958113724. Its totient is φ = 10770625200.

The previous prime is 21756663101. The next prime is 21756663107. The reversal of 21756663106 is 60136665712.

It can be written as a sum of positive squares in 2 ways, for example, as 17738244225 + 4018418881 = 133185^2 + 63391^2 .

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 (21756663101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53852925 + ... + 53853328.

Almost surely, 2^21756663106 is an apocalyptic number.

21756663106 is a deficient number, since it is larger than the sum of its proper divisors (11201450618).

21756663106 is a wasteful number, since it uses less digits than its factorization.

21756663106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107706356.

The product of its (nonzero) digits is 272160, while the sum is 43.

The spelling of 21756663106 in words is "twenty-one billion, seven hundred fifty-six million, six hundred sixty-three thousand, one hundred six".