21711110666878 has 16 divisors (see below), whose sum is σ = 33907876163280. Its totient is φ = 10417166251200.

The previous prime is 21711110666857. The next prime is 21711110666911. The reversal of 21711110666878 is 87866601111712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2170237968 + ... + 2170247971.

It is an arithmetic number, because the mean of its divisors is an integer number (2119242260205).

Almost surely, 2^{21711110666878} is an apocalyptic number.

21711110666878 is a deficient number, since it is larger than the sum of its proper divisors (12196765496402).

21711110666878 is a wasteful number, since it uses less digits than its factorization.

21711110666878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4340486043.

The product of its (nonzero) digits is 1354752, while the sum is 55.

The spelling of 21711110666878 in words is "twenty-one trillion, seven hundred eleven billion, one hundred ten million, six hundred sixty-six thousand, eight hundred seventy-eight".