73178561081 has 2 divisors, whose sum is σ = 73178561082. Its totient is φ = 73178561080.

The previous prime is 73178561017. The next prime is 73178561143. The reversal of 73178561081 is 18016587137.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70910896681 + 2267664400 = 266291^2 + 47620^2 .

It is a cyclic number.

It is not a de Polignac number, because 73178561081 - 2⁶ = 73178561017 is a prime.

It is a super-2 number, since 2×73178561081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (73178561011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36589280540 + 36589280541.

It is an arithmetic number, because the mean of its divisors is an integer number (36589280541).

Almost surely, 2^73178561081 is an apocalyptic number.

It is an amenable number.

73178561081 is a deficient number, since it is larger than the sum of its proper divisors (1).

73178561081 is an equidigital number, since it uses as much as digits as its factorization.

73178561081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 282240, while the sum is 47.

The spelling of 73178561081 in words is "seventy-three billion, one hundred seventy-eight million, five hundred sixty-one thousand, eighty-one".