3947778 has 24 divisors (see below), whose sum is σ = 8871408. Its totient is φ = 1315764.

The previous prime is 3947771. The next prime is 3947807. The reversal of 3947778 is 8777493.

It is a super-2 number, since 2×3947778² = 31169902274568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3947771) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3576 + ... + 4547.

It is an arithmetic number, because the mean of its divisors is an integer number (369642).

Almost surely, 2^3947778 is an apocalyptic number.

3947778 is an abundant number, since it is smaller than the sum of its proper divisors (4923630).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3947778 is an equidigital number, since it uses as much as digits as its factorization.

3947778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8140 (or 8128 counting only the distinct ones).

The product of its digits is 296352, while the sum is 45.

The square root of 3947778 is about 1986.9016080320. The cubic root of 3947778 is about 158.0462664272.

The spelling of 3947778 in words is "three million, nine hundred forty-seven thousand, seven hundred seventy-eight".