66394337294825 has 6 divisors (see below), whose sum is σ = 82328978245614. Its totient is φ = 53115469835840.

The previous prime is 66394337294821. The next prime is 66394337294891. The reversal of 66394337294825 is 52849273349366.

It can be written as a sum of positive squares in 3 ways, for example, as 2015105167936 + 64379232126889 = 1419544^2 + 8023667^2 .

It is not a de Polignac number, because 66394337294825 - 2² = 66394337294821 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66394337294821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1327886745872 + ... + 1327886745921.

It is an arithmetic number, because the mean of its divisors is an integer number (13721496374269).

Almost surely, 2^{66394337294825} is an apocalyptic number.

It is an amenable number.

66394337294825 is a deficient number, since it is larger than the sum of its proper divisors (15934640950789).

66394337294825 is a wasteful number, since it uses less digits than its factorization.

66394337294825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2655773491803 (or 2655773491798 counting only the distinct ones).

The product of its digits is 1410877440, while the sum is 71.

The spelling of 66394337294825 in words is "sixty-six trillion, three hundred ninety-four billion, three hundred thirty-seven million, two hundred ninety-four thousand, eight hundred twenty-five".