21116151515017 has 8 divisors (see below), whose sum is σ = 22741563972680. Its totient is φ = 19490895216000.

The previous prime is 21116151515003. The next prime is 21116151515023. The reversal of 21116151515017 is 71051515161112.

It can be written as a sum of positive squares in 4 ways, for example, as 1959633217161 + 19156518297856 = 1399869^2 + 4376816^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-21116151515017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21116151515057) 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, 38758734 + ... + 39299767.

It is an arithmetic number, because the mean of its divisors is an integer number (2842695496585).

Almost surely, 2^{21116151515017} is an apocalyptic number.

It is an amenable number.

21116151515017 is a deficient number, since it is larger than the sum of its proper divisors (1625412457663).

21116151515017 is a wasteful number, since it uses less digits than its factorization.

21116151515017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78079323.

The product of its (nonzero) digits is 10500, while the sum is 37.

Adding to 21116151515017 its reverse (71051515161112), we get a palindrome (92167666676129).

The spelling of 21116151515017 in words is "twenty-one trillion, one hundred sixteen billion, one hundred fifty-one million, five hundred fifteen thousand, seventeen".