21116216501 has 8 divisors (see below), whose sum is σ = 21389652480. Its totient is φ = 20843233632.

The previous prime is 21116216489. The next prime is 21116216503. The reversal of 21116216501 is 10561261112.

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 21116216501 - 2³⁰ = 20042474677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21116216503) 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, 18965 + ... + 206378.

It is an arithmetic number, because the mean of its divisors is an integer number (2673706560).

Almost surely, 2^21116216501 is an apocalyptic number.

It is an amenable number.

21116216501 is a deficient number, since it is larger than the sum of its proper divisors (273435979).

21116216501 is a wasteful number, since it uses less digits than its factorization.

21116216501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226555.

The product of its (nonzero) digits is 720, while the sum is 26.

Adding to 21116216501 its reverse (10561261112), we get a palindrome (31677477613).

The spelling of 21116216501 in words is "twenty-one billion, one hundred sixteen million, two hundred sixteen thousand, five hundred one".