21187326066 has 32 divisors (see below), whose sum is σ = 44881750080. Its totient is φ = 6644860416.

The previous prime is 21187326023. The next prime is 21187326073. The reversal of 21187326066 is 66062378112.

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, 300550 + ... + 364286.

It is an arithmetic number, because the mean of its divisors is an integer number (1402554690).

Almost surely, 2^21187326066 is an apocalyptic number.

21187326066 is an abundant number, since it is smaller than the sum of its proper divisors (23694424014).

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

21187326066 is a wasteful number, since it uses less digits than its factorization.

21187326066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67018.

The product of its (nonzero) digits is 145152, while the sum is 42.

The spelling of 21187326066 in words is "twenty-one billion, one hundred eighty-seven million, three hundred twenty-six thousand, sixty-six".