21066105215 has 16 divisors (see below), whose sum is σ = 25984804320. Its totient is φ = 16383346560.

The previous prime is 21066105173. The next prime is 21066105233. The reversal of 21066105215 is 51250166012.

It is a happy number.

It is not a de Polignac number, because 21066105215 - 2²⁸ = 20797669759 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170276 + ... + 266694.

It is an arithmetic number, because the mean of its divisors is an integer number (1624050270).

Almost surely, 2^21066105215 is an apocalyptic number.

21066105215 is a deficient number, since it is larger than the sum of its proper divisors (4918699105).

21066105215 is a wasteful number, since it uses less digits than its factorization.

21066105215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97642.

The product of its (nonzero) digits is 3600, while the sum is 29.

The spelling of 21066105215 in words is "twenty-one billion, sixty-six million, one hundred five thousand, two hundred fifteen".