21121534536 has 32 divisors (see below), whose sum is σ = 55909945440. Its totient is φ = 6626363648.

The previous prime is 21121534523. The next prime is 21121534537. The reversal of 21121534536 is 63543512112.

It is a super-2 number, since 2×21121534536² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121534497 and 21121534506.

It is not an unprimeable number, because it can be changed into a prime (21121534537) 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, 25883826 + ... + 25884641.

It is an arithmetic number, because the mean of its divisors is an integer number (1747185795).

Almost surely, 2^21121534536 is an apocalyptic number.

It is an amenable number.

21121534536 is an abundant number, since it is smaller than the sum of its proper divisors (34788410904).

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

21121534536 is a wasteful number, since it uses less digits than its factorization.

21121534536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51768493 (or 51768489 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The spelling of 21121534536 in words is "twenty-one billion, one hundred twenty-one million, five hundred thirty-four thousand, five hundred thirty-six".