2505456661 has 2 divisors, whose sum is σ = 2505456662. Its totient is φ = 2505456660.

The previous prime is 2505456643. The next prime is 2505456697. The reversal of 2505456661 is 1666545052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1616522436 + 888934225 = 40206^2 + 29815^2 .

It is a cyclic number.

It is not a de Polignac number, because 2505456661 - 2¹³ = 2505448469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2505456761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1252728330 + 1252728331.

It is an arithmetic number, because the mean of its divisors is an integer number (1252728331).

Almost surely, 2^2505456661 is an apocalyptic number.

It is an amenable number.

2505456661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2505456661 is an equidigital number, since it uses as much as digits as its factorization.

2505456661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216000, while the sum is 40.

The square root of 2505456661 is about 50054.5368673010. The cubic root of 2505456661 is about 1358.1955345310.

The spelling of 2505456661 in words is "two billion, five hundred five million, four hundred fifty-six thousand, six hundred sixty-one".