21066342644 has 48 divisors (see below), whose sum is σ = 39915832320. Its totient is φ = 9694339200.

The previous prime is 21066342629. The next prime is 21066342673. The reversal of 21066342644 is 44624366012.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 21066342598 and 21066342607.

It is a congruent number.

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, 1965869 + ... + 1976555.

It is an arithmetic number, because the mean of its divisors is an integer number (831579840).

Almost surely, 2^21066342644 is an apocalyptic number.

It is an amenable number.

21066342644 is a deficient number, since it is larger than the sum of its proper divisors (18849489676).

21066342644 is a wasteful number, since it uses less digits than its factorization.

21066342644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11448 (or 11446 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 38.

The spelling of 21066342644 in words is "twenty-one billion, sixty-six million, three hundred forty-two thousand, six hundred forty-four".