201565198649 has 2 divisors, whose sum is σ = 201565198650. Its totient is φ = 201565198648.

The previous prime is 201565198631. The next prime is 201565198661. The reversal of 201565198649 is 946891565102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197438035600 + 4127163049 = 444340^2 + 64243^2 .

It is a cyclic number.

It is not a de Polignac number, because 201565198649 - 2²⁴ = 201548421433 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201565198594 and 201565198603.

It is not a weakly prime, because it can be changed into another prime (201565198619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100782599324 + 100782599325.

It is an arithmetic number, because the mean of its divisors is an integer number (100782599325).

Almost surely, 2^201565198649 is an apocalyptic number.

It is an amenable number.

201565198649 is a deficient number, since it is larger than the sum of its proper divisors (1).

201565198649 is an equidigital number, since it uses as much as digits as its factorization.

201565198649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4665600, while the sum is 56.

The spelling of 201565198649 in words is "two hundred one billion, five hundred sixty-five million, one hundred ninety-eight thousand, six hundred forty-nine".