215040745021 has 2 divisors, whose sum is σ = 215040745022. Its totient is φ = 215040745020.

The previous prime is 215040744973. The next prime is 215040745039. The reversal of 215040745021 is 120547040512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150415987225 + 64624757796 = 387835^2 + 254214^2 .

It is a cyclic number.

It is not a de Polignac number, because 215040745021 - 2¹⁵ = 215040712253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215040745721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107520372510 + 107520372511.

It is an arithmetic number, because the mean of its divisors is an integer number (107520372511).

Almost surely, 2^215040745021 is an apocalyptic number.

It is an amenable number.

215040745021 is a deficient number, since it is larger than the sum of its proper divisors (1).

215040745021 is an equidigital number, since it uses as much as digits as its factorization.

215040745021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11200, while the sum is 31.

Adding to 215040745021 its reverse (120547040512), we get a palindrome (335587785533).

The spelling of 215040745021 in words is "two hundred fifteen billion, forty million, seven hundred forty-five thousand, twenty-one".