21993071232 has 128 divisors (see below), whose sum is σ = 63787046400. Its totient is φ = 6658595840.

The previous prime is 21993071231. The next prime is 21993071249. The reversal of 21993071232 is 23217039912.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (21993071231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7800319 + ... + 7803137.

It is an arithmetic number, because the mean of its divisors is an integer number (498336300).

Almost surely, 2^21993071232 is an apocalyptic number.

21993071232 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21993071232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31893523200).

21993071232 is an abundant number, since it is smaller than the sum of its proper divisors (41793975168).

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

21993071232 is a wasteful number, since it uses less digits than its factorization.

21993071232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4694 (or 4682 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 39.

The spelling of 21993071232 in words is "twenty-one billion, nine hundred ninety-three million, seventy-one thousand, two hundred thirty-two".