542061565561 has 2 divisors, whose sum is σ = 542061565562. Its totient is φ = 542061565560.

The previous prime is 542061565537. The next prime is 542061565583. The reversal of 542061565561 is 165565160245.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 537868226025 + 4193339536 = 733395^2 + 64756^2 .

It is a cyclic number.

It is not a de Polignac number, because 542061565561 - 2⁹ = 542061565049 is a prime.

It is not a weakly prime, because it can be changed into another prime (542061565511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 271030782780 + 271030782781.

It is an arithmetic number, because the mean of its divisors is an integer number (271030782781).

Almost surely, 2^542061565561 is an apocalyptic number.

It is an amenable number.

542061565561 is a deficient number, since it is larger than the sum of its proper divisors (1).

542061565561 is an equidigital number, since it uses as much as digits as its factorization.

542061565561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080000, while the sum is 46.

The spelling of 542061565561 in words is "five hundred forty-two billion, sixty-one million, five hundred sixty-five thousand, five hundred sixty-one".