3787681 has 4 divisors (see below), whose sum is σ = 3791664. Its totient is φ = 3783700.

The previous prime is 3787657. The next prime is 3787687. The reversal of 3787681 is 1867873.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1867873 = 7 ⋅266839.

It is a cyclic number.

It is not a de Polignac number, because 3787681 - 2⁵ = 3787649 is a prime.

It is a super-2 number, since 2×3787681² = 28693054715522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3787687) 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, 366 + ... + 2776.

It is an arithmetic number, because the mean of its divisors is an integer number (947916).

Almost surely, 2^3787681 is an apocalyptic number.

It is an amenable number.

3787681 is a deficient number, since it is larger than the sum of its proper divisors (3983).

3787681 is a wasteful number, since it uses less digits than its factorization.

3787681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3982.

The product of its digits is 56448, while the sum is 40.

The square root of 3787681 is about 1946.1965471144. The cubic root of 3787681 is about 155.8802636985.

The spelling of 3787681 in words is "three million, seven hundred eighty-seven thousand, six hundred eighty-one".