545991506681 has 2 divisors, whose sum is σ = 545991506682. Its totient is φ = 545991506680.

The previous prime is 545991506677. The next prime is 545991506693. The reversal of 545991506681 is 186605199545.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 439383379600 + 106608127081 = 662860^2 + 326509^2 .

It is a cyclic number.

It is not a de Polignac number, because 545991506681 - 2² = 545991506677 is a prime.

It is a super-2 number, since 2×545991506681² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 545991506681.

It is not a weakly prime, because it can be changed into another prime (545991506651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 272995753340 + 272995753341.

It is an arithmetic number, because the mean of its divisors is an integer number (272995753341).

Almost surely, 2^545991506681 is an apocalyptic number.

It is an amenable number.

545991506681 is a deficient number, since it is larger than the sum of its proper divisors (1).

545991506681 is an equidigital number, since it uses as much as digits as its factorization.

545991506681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664000, while the sum is 59.

The spelling of 545991506681 in words is "five hundred forty-five billion, nine hundred ninety-one million, five hundred six thousand, six hundred eighty-one".