361861681 has 4 divisors (see below), whose sum is σ = 374339700. Its totient is φ = 349383664.

The previous prime is 361861679. The next prime is 361861723. The reversal of 361861681 is 186168163.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 98903025 + 262958656 = 9945^2 + 16216^2 .

It is a cyclic number.

It is not a de Polignac number, because 361861681 - 2¹ = 361861679 is a prime.

It is a super-2 number, since 2×361861681² = 261887752352291522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (361861781) 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, 6238966 + ... + 6239023.

It is an arithmetic number, because the mean of its divisors is an integer number (93584925).

Almost surely, 2^361861681 is an apocalyptic number.

It is an amenable number.

361861681 is a deficient number, since it is larger than the sum of its proper divisors (12478019).

361861681 is a wasteful number, since it uses less digits than its factorization.

361861681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12478018.

The product of its digits is 41472, while the sum is 40.

The square root of 361861681 is about 19022.6623005299. The cubic root of 361861681 is about 712.6028125361.

The spelling of 361861681 in words is "three hundred sixty-one million, eight hundred sixty-one thousand, six hundred eighty-one".