1021116521 has 8 divisors (see below), whose sum is σ = 1046658984. Its totient is φ = 995604480.

The previous prime is 1021116517. The next prime is 1021116617. The reversal of 1021116521 is 1256111201.

It can be written as a sum of positive squares in 4 ways, for example, as 290225296 + 730891225 = 17036^2 + 27035^2 .

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 1021116521 - 2² = 1021116517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021116493 and 1021116502.

It is not an unprimeable number, because it can be changed into a prime (1021116721) 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, 70145 + ... + 83441.

It is an arithmetic number, because the mean of its divisors is an integer number (130832373).

Almost surely, 2^1021116521 is an apocalyptic number.

It is an amenable number.

1021116521 is a deficient number, since it is larger than the sum of its proper divisors (25542463).

1021116521 is a wasteful number, since it uses less digits than its factorization.

1021116521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15211.

The product of its (nonzero) digits is 120, while the sum is 20.

The square root of 1021116521 is about 31954.9138787761. The cubic root of 1021116521 is about 1006.9898682378.

Adding to 1021116521 its reverse (1256111201), we get a palindrome (2277227722).

The spelling of 1021116521 in words is "one billion, twenty-one million, one hundred sixteen thousand, five hundred twenty-one".