21145500066 has 32 divisors (see below), whose sum is σ = 42507813888. Its totient is φ = 7012455120.

The previous prime is 21145500059. The next prime is 21145500071. The reversal of 21145500066 is 66000554112.

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 15 ways as a sum of consecutive naturals, for example, 956251 + ... + 978113.

It is an arithmetic number, because the mean of its divisors is an integer number (1328369184).

Almost surely, 2^21145500066 is an apocalyptic number.

21145500066 is an abundant number, since it is smaller than the sum of its proper divisors (21362313822).

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

21145500066 is a wasteful number, since it uses less digits than its factorization.

21145500066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22686.

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21145500066 in words is "twenty-one billion, one hundred forty-five million, five hundred thousand, sixty-six".