181367746261 has 4 divisors (see below), whose sum is σ = 195319111372. Its totient is φ = 167416381152.

The previous prime is 181367746237. The next prime is 181367746267. The reversal of 181367746261 is 162647763181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 162647763181 = 2741 ⋅59338841.

It can be written as a sum of positive squares in 2 ways, for example, as 120540896100 + 60826850161 = 347190^2 + 246631^2 .

It is a cyclic number.

It is not a de Polignac number, because 181367746261 - 2¹⁷ = 181367615189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 181367746199 and 181367746208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181367746267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6975682536 + ... + 6975682561.

It is an arithmetic number, because the mean of its divisors is an integer number (48829777843).

Almost surely, 2^181367746261 is an apocalyptic number.

It is an amenable number.

181367746261 is a deficient number, since it is larger than the sum of its proper divisors (13951365111).

181367746261 is a wasteful number, since it uses less digits than its factorization.

181367746261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13951365110.

The product of its digits is 2032128, while the sum is 52.

The spelling of 181367746261 in words is "one hundred eighty-one billion, three hundred sixty-seven million, seven hundred forty-six thousand, two hundred sixty-one".