21216416331 has 8 divisors (see below), whose sum is σ = 30860241984. Its totient is φ = 12858434120.

The previous prime is 21216416323. The next prime is 21216416357. The reversal of 21216416331 is 13361461212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21216416331 - 2³ = 21216416323 is a prime.

It is a super-2 number, since 2×21216416331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21216416131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 321460821 + ... + 321460886.

It is an arithmetic number, because the mean of its divisors is an integer number (3857530248).

Almost surely, 2^21216416331 is an apocalyptic number.

21216416331 is a deficient number, since it is larger than the sum of its proper divisors (9643825653).

21216416331 is a wasteful number, since it uses less digits than its factorization.

21216416331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642921721.

The product of its digits is 5184, while the sum is 30.

Adding to 21216416331 its reverse (13361461212), we get a palindrome (34577877543).

The spelling of 21216416331 in words is "twenty-one billion, two hundred sixteen million, four hundred sixteen thousand, three hundred thirty-one".