21612655621612 has 96 divisors (see below), whose sum is σ = 41933145623040. Its totient is φ = 9665266560000.

The previous prime is 21612655621597. The next prime is 21612655621651.

21612655621612 is nontrivially palindromic in base 10.

21612655621612 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21612655621612² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 432305937 + ... + 432355927.

It is an arithmetic number, because the mean of its divisors is an integer number (436803600240).

Almost surely, 2^{21612655621612} is an apocalyptic number.

21612655621612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21612655621612 is a deficient number, since it is larger than the sum of its proper divisors (20320490001428).

21612655621612 is a wasteful number, since it uses less digits than its factorization.

21612655621612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50743 (or 50741 counting only the distinct ones).

The product of its digits is 518400, while the sum is 46.

It can be divided in two parts, 2161265 and 5621612, that added together give a palindrome (7782877).

The spelling of 21612655621612 in words is "twenty-one trillion, six hundred twelve billion, six hundred fifty-five million, six hundred twenty-one thousand, six hundred twelve".