21216224015444 has 12 divisors (see below), whose sum is σ = 37682547132384. Its totient is φ = 10449781977624.

The previous prime is 21216224015419. The next prime is 21216224015461. The reversal of 21216224015444 is 44451042261212.

It is a super-2 number, since 2×21216224015444² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21216224015398 and 21216224015407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39582507224 + ... + 39582507759.

It is an arithmetic number, because the mean of its divisors is an integer number (3140212261032).

Almost surely, 2^{21216224015444} is an apocalyptic number.

It is an amenable number.

21216224015444 is a deficient number, since it is larger than the sum of its proper divisors (16466323116940).

21216224015444 is a wasteful number, since it uses less digits than its factorization.

21216224015444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79165015054 (or 79165015052 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 38.

Adding to 21216224015444 its reverse (44451042261212), we get a palindrome (65667266276656).

The spelling of 21216224015444 in words is "twenty-one trillion, two hundred sixteen billion, two hundred twenty-four million, fifteen thousand, four hundred forty-four".