21216403303407 has 32 divisors (see below), whose sum is σ = 33850825041600. Its totient is φ = 13055749572096.

The previous prime is 21216403303387. The next prime is 21216403303409. The reversal of 21216403303407 is 70430330461212.

21216403303407 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 640 + 3 + 3 + 0 + 3 + 4 + 0 + 7 = 666.

It is not a de Polignac number, because 21216403303407 - 2¹⁸ = 21216403041263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21216403303409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8156683 + ... + 10438595.

It is an arithmetic number, because the mean of its divisors is an integer number (1057838282550).

Almost surely, 2^{21216403303407} is an apocalyptic number.

21216403303407 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21216403303407 is a deficient number, since it is larger than the sum of its proper divisors (12634421738193).

21216403303407 is a wasteful number, since it uses less digits than its factorization.

21216403303407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2308424 (or 2308418 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

Adding to 21216403303407 its reverse (70430330461212), we get a palindrome (91646733764619).

The spelling of 21216403303407 in words is "twenty-one trillion, two hundred sixteen billion, four hundred three million, three hundred three thousand, four hundred seven".