21336646044 has 72 divisors (see below), whose sum is σ = 58564613520. Its totient is φ = 6027673344.

The previous prime is 21336646043. The next prime is 21336646057. The reversal of 21336646044 is 44064663312.

It is a junction number, because it is equal to n+sod(n) for n = 21336645993 and 21336646011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21336646043) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 151527 + ... + 256190.

It is an arithmetic number, because the mean of its divisors is an integer number (813397410).

Almost surely, 2^21336646044 is an apocalyptic number.

It is an amenable number.

21336646044 is an abundant number, since it is smaller than the sum of its proper divisors (37227967476).

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

21336646044 is a wasteful number, since it uses less digits than its factorization.

21336646044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407827 (or 407818 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 39.

The spelling of 21336646044 in words is "twenty-one billion, three hundred thirty-six million, six hundred forty-six thousand, forty-four".