3947855 has 4 divisors (see below), whose sum is σ = 4737432. Its totient is φ = 3158280.

The previous prime is 3947851. The next prime is 3947861. The reversal of 3947855 is 5587493.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5587493 = 73 ⋅76541.

It is not a de Polignac number, because 3947855 - 2² = 3947851 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3947851) 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, 394781 + ... + 394790.

It is an arithmetic number, because the mean of its divisors is an integer number (1184358).

Almost surely, 2^3947855 is an apocalyptic number.

3947855 is a deficient number, since it is larger than the sum of its proper divisors (789577).

3947855 is an equidigital number, since it uses as much as digits as its factorization.

3947855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789576.

The product of its digits is 151200, while the sum is 41.

The square root of 3947855 is about 1986.9209848406. The cubic root of 3947855 is about 158.0472939658.

The spelling of 3947855 in words is "three million, nine hundred forty-seven thousand, eight hundred fifty-five".