21121335215504 has 10 divisors (see below), whose sum is σ = 40922586980070. Its totient is φ = 10560667607744.

The previous prime is 21121335215501. The next prime is 21121335215521. The reversal of 21121335215504 is 40551253312112.

It can be written as a sum of positive squares in only one way, i.e., 14206265574400 + 6915069641104 = 3769120^2 + 2629652^2 .

It is a super-2 number, since 2×21121335215504² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121335215501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660041725469 + ... + 660041725500.

It is an arithmetic number, because the mean of its divisors is an integer number (4092258698007).

Almost surely, 2^{21121335215504} is an apocalyptic number.

It is an amenable number.

21121335215504 is a deficient number, since it is larger than the sum of its proper divisors (19801251764566).

21121335215504 is a wasteful number, since it uses less digits than its factorization.

21121335215504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320083450977 (or 1320083450971 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 35.

Adding to 21121335215504 its reverse (40551253312112), we get a palindrome (61672588527616).

The spelling of 21121335215504 in words is "twenty-one trillion, one hundred twenty-one billion, three hundred thirty-five million, two hundred fifteen thousand, five hundred four".