21090940405266 has 64 divisors (see below), whose sum is σ = 45360305971200. Its totient is φ = 6516633067776.

The previous prime is 21090940405243. The next prime is 21090940405303. The reversal of 21090940405266 is 66250404909012.

It is an unprimeable number.

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, 17323050 + ... + 18500538.

It is an arithmetic number, because the mean of its divisors is an integer number (708754780800).

Almost surely, 2^{21090940405266} is an apocalyptic number.

21090940405266 is an abundant number, since it is smaller than the sum of its proper divisors (24269365565934).

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

21090940405266 is a wasteful number, since it uses less digits than its factorization.

21090940405266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180903.

The product of its (nonzero) digits is 933120, while the sum is 48.

The spelling of 21090940405266 in words is "twenty-one trillion, ninety billion, nine hundred forty million, four hundred five thousand, two hundred sixty-six".