3651681 has 16 divisors (see below), whose sum is σ = 5345280. Its totient is φ = 2199120.

The previous prime is 3651673. The next prime is 3651731. The reversal of 3651681 is 1861563.

It is not a de Polignac number, because 3651681 - 2³ = 3651673 is a prime.

It is a super-2 number, since 2×3651681² = 26669548251522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3651611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7656 + ... + 8118.

It is an arithmetic number, because the mean of its divisors is an integer number (334080).

Almost surely, 2^3651681 is an apocalyptic number.

It is an amenable number.

3651681 is a deficient number, since it is larger than the sum of its proper divisors (1693599).

3651681 is a wasteful number, since it uses less digits than its factorization.

3651681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716.

The product of its digits is 4320, while the sum is 30.

The square root of 3651681 is about 1910.9372046198. The cubic root of 3651681 is about 153.9918053772.

The spelling of 3651681 in words is "three million, six hundred fifty-one thousand, six hundred eighty-one".