2145116521 has 2 divisors, whose sum is σ = 2145116522. Its totient is φ = 2145116520.

The previous prime is 2145116497. The next prime is 2145116557. The reversal of 2145116521 is 1256115412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2055624921 + 89491600 = 45339^2 + 9460^2 .

It is a cyclic number.

It is not a de Polignac number, because 2145116521 - 2⁹ = 2145116009 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2145116521.

It is not a weakly prime, because it can be changed into another prime (2145116221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1072558260 + 1072558261.

It is an arithmetic number, because the mean of its divisors is an integer number (1072558261).

Almost surely, 2^2145116521 is an apocalyptic number.

It is an amenable number.

2145116521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2145116521 is an equidigital number, since it uses as much as digits as its factorization.

2145116521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 28.

The square root of 2145116521 is about 46315.4026323857. The cubic root of 2145116521 is about 1289.6849421889.

The spelling of 2145116521 in words is "two billion, one hundred forty-five million, one hundred sixteen thousand, five hundred twenty-one".