21216403303443 has 48 divisors (see below), whose sum is σ = 32531773944384. Its totient is φ = 13296477680640.

The previous prime is 21216403303409. The next prime is 21216403303483. The reversal of 21216403303443 is 34430330461212.

It is a happy number.

21216403303443 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 640 + 3 + 3 + 0 + 3 + 4 + 4 + 3 = 666.

It is not a de Polignac number, because 21216403303443 - 2²¹ = 21216401206291 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21216403303398 and 21216403303407.

It is not an unprimeable number, because it can be changed into a prime (21216403303483) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1747905 + ... + 6744477.

It is an arithmetic number, because the mean of its divisors is an integer number (677745290508).

Almost surely, 2^{21216403303443} is an apocalyptic number.

21216403303443 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21216403303443 is a deficient number, since it is larger than the sum of its proper divisors (11315370640941).

21216403303443 is a wasteful number, since it uses less digits than its factorization.

21216403303443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4996956 (or 4996953 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 36.

Adding to 21216403303443 its reverse (34430330461212), we get a palindrome (55646733764655).

The spelling of 21216403303443 in words is "twenty-one trillion, two hundred sixteen billion, four hundred three million, three hundred three thousand, four hundred forty-three".