21659145784 has 64 divisors (see below), whose sum is σ = 42903691200. Its totient is φ = 10234957824.

The previous prime is 21659145773. The next prime is 21659145787. The reversal of 21659145784 is 48754195612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21659145787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5986344 + ... + 5989960.

It is an arithmetic number, because the mean of its divisors is an integer number (670370175).

Almost surely, 2^21659145784 is an apocalyptic number.

It is an amenable number.

21659145784 is a deficient number, since it is larger than the sum of its proper divisors (21244545416).

21659145784 is a wasteful number, since it uses less digits than its factorization.

21659145784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4192 (or 4188 counting only the distinct ones).

The product of its digits is 2419200, while the sum is 52.

The spelling of 21659145784 in words is "twenty-one billion, six hundred fifty-nine million, one hundred forty-five thousand, seven hundred eighty-four".