2045511661 has 2 divisors, whose sum is σ = 2045511662. Its totient is φ = 2045511660.

The previous prime is 2045511641. The next prime is 2045511679. The reversal of 2045511661 is 1661155402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1467349636 + 578162025 = 38306^2 + 24045^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2045511661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2045511641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1022755830 + 1022755831.

It is an arithmetic number, because the mean of its divisors is an integer number (1022755831).

Almost surely, 2^2045511661 is an apocalyptic number.

It is an amenable number.

2045511661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2045511661 is an equidigital number, since it uses as much as digits as its factorization.

2045511661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 2045511661 is about 45227.3331183699. Note that the first 3 decimals coincide. The cubic root of 2045511661 is about 1269.4063112639.

The spelling of 2045511661 in words is "two billion, forty-five million, five hundred eleven thousand, six hundred sixty-one".