661005099949 has 2 divisors, whose sum is σ = 661005099950. Its totient is φ = 661005099948.

The previous prime is 661005099947. The next prime is 661005099983. The reversal of 661005099949 is 949990500166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608779139049 + 52225960900 = 780243^2 + 228530^2 .

It is a cyclic number.

It is not a de Polignac number, because 661005099949 - 2¹ = 661005099947 is a prime.

Together with 661005099947, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 661005099893 and 661005099902.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661005099941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330502549974 + 330502549975.

It is an arithmetic number, because the mean of its divisors is an integer number (330502549975).

Almost surely, 2^661005099949 is an apocalyptic number.

It is an amenable number.

661005099949 is a deficient number, since it is larger than the sum of its proper divisors (1).

661005099949 is an equidigital number, since it uses as much as digits as its factorization.

661005099949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4723920, while the sum is 58.

The spelling of 661005099949 in words is "six hundred sixty-one billion, five million, ninety-nine thousand, nine hundred forty-nine".