21633297972 has 96 divisors (see below), whose sum is σ = 59465785344. Its totient is φ = 6034608000.

The previous prime is 21633297947. The next prime is 21633297977. The reversal of 21633297972 is 27979233612.

It is a super-2 number, since 2×21633297972² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633297977) 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 31 ways as a sum of consecutive naturals, for example, 612597 + ... + 646947.

It is an arithmetic number, because the mean of its divisors is an integer number (619435264).

Almost surely, 2^21633297972 is an apocalyptic number.

21633297972 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 21633297972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29732892672).

21633297972 is an abundant number, since it is smaller than the sum of its proper divisors (37832487372).

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

21633297972 is a wasteful number, since it uses less digits than its factorization.

21633297972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34749 (or 34747 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 51.

The spelling of 21633297972 in words is "twenty-one billion, six hundred thirty-three million, two hundred ninety-seven thousand, nine hundred seventy-two".