215215512202661 has 2 divisors, whose sum is σ = 215215512202662. Its totient is φ = 215215512202660.

The previous prime is 215215512202633. The next prime is 215215512202729. The reversal of 215215512202661 is 166202215512512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125303509149025 + 89912003053636 = 11193905^2 + 9482194^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215215512202661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215215517202661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107607756101330 + 107607756101331.

It is an arithmetic number, because the mean of its divisors is an integer number (107607756101331).

Almost surely, 2^{215215512202661} is an apocalyptic number.

It is an amenable number.

215215512202661 is a deficient number, since it is larger than the sum of its proper divisors (1).

215215512202661 is an equidigital number, since it uses as much as digits as its factorization.

215215512202661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144000, while the sum is 41.

The spelling of 215215512202661 in words is "two hundred fifteen trillion, two hundred fifteen billion, five hundred twelve million, two hundred two thousand, six hundred sixty-one".