21730335136 has 48 divisors (see below), whose sum is σ = 45526017600. Its totient is φ = 10174602240.

The previous prime is 21730335113. The next prime is 21730335139. The reversal of 21730335136 is 63153303712.

It is a super-2 number, since 2×21730335136² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (21730335139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7891 + ... + 208621.

It is an arithmetic number, because the mean of its divisors is an integer number (948458700).

Almost surely, 2^21730335136 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 21730335136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22763008800).

21730335136 is an abundant number, since it is smaller than the sum of its proper divisors (23795682464).

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

21730335136 is a wasteful number, since it uses less digits than its factorization.

21730335136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200957 (or 200949 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 34.

Adding to 21730335136 its reverse (63153303712), we get a palindrome (84883638848).

The spelling of 21730335136 in words is "twenty-one billion, seven hundred thirty million, three hundred thirty-five thousand, one hundred thirty-six".