21216111230452 has 48 divisors (see below), whose sum is σ = 38355944094720. Its totient is φ = 10261928851200.

The previous prime is 21216111230429. The next prime is 21216111230467. The reversal of 21216111230452 is 25403211161212.

It is a super-2 number, since 2×21216111230452² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11473177 + ... + 13193407.

It is an arithmetic number, because the mean of its divisors is an integer number (799082168640).

Almost surely, 2^{21216111230452} is an apocalyptic number.

It is an amenable number.

21216111230452 is a deficient number, since it is larger than the sum of its proper divisors (17139832864268).

21216111230452 is a wasteful number, since it uses less digits than its factorization.

21216111230452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720912 (or 1720910 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

Adding to 21216111230452 its reverse (25403211161212), we get a palindrome (46619322391664).

The spelling of 21216111230452 in words is "twenty-one trillion, two hundred sixteen billion, one hundred eleven million, two hundred thirty thousand, four hundred fifty-two".