21785879232 has 378 divisors, whose sum is σ = 70444121748. Its totient is φ = 6681512448.

The previous prime is 21785879201. The next prime is 21785879233. The reversal of 21785879232 is 23297858712.

21785879232 is a `hidden beast` number, since 21 + 7 + 8 + 587 + 9 + 2 + 32 = 666.

It is a super-2 number, since 2×21785879232² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21785879233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 70963623 + ... + 70963929.

Almost surely, 2^21785879232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21785879232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35222060874).

21785879232 is an abundant number, since it is smaller than the sum of its proper divisors (48658242516).

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

21785879232 is an frugal number, since it uses more digits than its factorization.

21785879232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 325 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The spelling of 21785879232 in words is "twenty-one billion, seven hundred eighty-five million, eight hundred seventy-nine thousand, two hundred thirty-two".