21401873407866 has 64 divisors (see below), whose sum is σ = 51682126049280. Its totient is φ = 5778348784320.

The previous prime is 21401873407861. The next prime is 21401873407879. The reversal of 21401873407866 is 66870437810412.

It is not an unprimeable number, because it can be changed into a prime (21401873407861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186871740 + ... + 186986231.

It is an arithmetic number, because the mean of its divisors is an integer number (807533219520).

Almost surely, 2^{21401873407866} is an apocalyptic number.

21401873407866 is an abundant number, since it is smaller than the sum of its proper divisors (30280252641414).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21401873407866 is a wasteful number, since it uses less digits than its factorization.

21401873407866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373858059.

The product of its (nonzero) digits is 10838016, while the sum is 57.

The spelling of 21401873407866 in words is "twenty-one trillion, four hundred one billion, eight hundred seventy-three million, four hundred seven thousand, eight hundred sixty-six".