660025513561 has 2 divisors, whose sum is σ = 660025513562. Its totient is φ = 660025513560.

The previous prime is 660025513531. The next prime is 660025513577. The reversal of 660025513561 is 165315520066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 551870694400 + 108154819161 = 742880^2 + 328869^2 .

It is a cyclic number.

It is not a de Polignac number, because 660025513561 - 2²⁹ = 659488642649 is a prime.

It is not a weakly prime, because it can be changed into another prime (660025513531) 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, 330012756780 + 330012756781.

It is an arithmetic number, because the mean of its divisors is an integer number (330012756781).

Almost surely, 2^660025513561 is an apocalyptic number.

It is an amenable number.

660025513561 is a deficient number, since it is larger than the sum of its proper divisors (1).

660025513561 is an equidigital number, since it uses as much as digits as its factorization.

660025513561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162000, while the sum is 40.

The spelling of 660025513561 in words is "six hundred sixty billion, twenty-five million, five hundred thirteen thousand, five hundred sixty-one".