21106213616 has 20 divisors (see below), whose sum is σ = 40899493872. Its totient is φ = 10551505536.

The previous prime is 21106213591. The next prime is 21106213637. The reversal of 21106213616 is 61631260112.

It is a happy number.

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, 12500 + ... + 205836.

Almost surely, 2^21106213616 is an apocalyptic number.

It is an amenable number.

21106213616 is a deficient number, since it is larger than the sum of its proper divisors (19793280256).

21106213616 is a wasteful number, since it uses less digits than its factorization.

21106213616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200168 (or 200162 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

Adding to 21106213616 its reverse (61631260112), we get a palindrome (82737473728).

The spelling of 21106213616 in words is "twenty-one billion, one hundred six million, two hundred thirteen thousand, six hundred sixteen".