21511011017 has 8 divisors (see below), whose sum is σ = 21760502400. Its totient is φ = 21261693024.

The previous prime is 21511010999. The next prime is 21511011061. The reversal of 21511011017 is 71011011512.

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 21511011017 - 2²² = 21506816713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21511011017.

It is not an unprimeable number, because it can be changed into a prime (21511011917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215084 + ... + 298802.

It is an arithmetic number, because the mean of its divisors is an integer number (2720062800).

Almost surely, 2^21511011017 is an apocalyptic number.

It is an amenable number.

21511011017 is a deficient number, since it is larger than the sum of its proper divisors (249491383).

21511011017 is an equidigital number, since it uses as much as digits as its factorization.

21511011017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86695.

The product of its (nonzero) digits is 70, while the sum is 20.

Adding to 21511011017 its reverse (71011011512), we get a palindrome (92522022529).

The spelling of 21511011017 in words is "twenty-one billion, five hundred eleven million, eleven thousand, seventeen".