21106742187 has 32 divisors (see below), whose sum is σ = 29708098560. Its totient is φ = 13316094720.

The previous prime is 21106742141. The next prime is 21106742273. The reversal of 21106742187 is 78124760112.

It is not a de Polignac number, because 21106742187 - 2¹⁰ = 21106741163 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21106742117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 486663 + ... + 528255.

It is an arithmetic number, because the mean of its divisors is an integer number (928378080).

Almost surely, 2^21106742187 is an apocalyptic number.

21106742187 is a deficient number, since it is larger than the sum of its proper divisors (8601356373).

21106742187 is a wasteful number, since it uses less digits than its factorization.

21106742187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41763.

The product of its (nonzero) digits is 37632, while the sum is 39.

The spelling of 21106742187 in words is "twenty-one billion, one hundred six million, seven hundred forty-two thousand, one hundred eighty-seven".