3661813 has 8 divisors (see below), whose sum is σ = 3979520. Its totient is φ = 3356640.

The previous prime is 3661781. The next prime is 3661831. The reversal of 3661813 is 3181663.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3661813 - 2⁵ = 3661781 is a prime.

It is a Duffinian number.

3661813 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3661913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2520 + ... + 3697.

It is an arithmetic number, because the mean of its divisors is an integer number (497440).

Almost surely, 2^3661813 is an apocalyptic number.

It is an amenable number.

3661813 is a deficient number, since it is larger than the sum of its proper divisors (317707).

3661813 is a wasteful number, since it uses less digits than its factorization.

3661813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6267.

The product of its digits is 2592, while the sum is 28.

The square root of 3661813 is about 1913.5864234468. The cubic root of 3661813 is about 154.1340963903.

The spelling of 3661813 in words is "three million, six hundred sixty-one thousand, eight hundred thirteen".