3991355 has 4 divisors (see below), whose sum is σ = 4789632. Its totient is φ = 3193080.

The previous prime is 3991333. The next prime is 3991369. The reversal of 3991355 is 5531993.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 3991355 - 2¹⁰ = 3990331 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 399131 + ... + 399140.

It is an arithmetic number, because the mean of its divisors is an integer number (1197408).

Almost surely, 2^3991355 is an apocalyptic number.

3991355 is a deficient number, since it is larger than the sum of its proper divisors (798277).

3991355 is an equidigital number, since it uses as much as digits as its factorization.

3991355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798276.

The product of its digits is 18225, while the sum is 35.

The square root of 3991355 is about 1997.8375809860. The cubic root of 3991355 is about 158.6256636942.

The spelling of 3991355 in words is "three million, nine hundred ninety-one thousand, three hundred fifty-five".