3971555 has 16 divisors (see below), whose sum is σ = 5552064. Its totient is φ = 2670720.

The previous prime is 3971549. The next prime is 3971581. The reversal of 3971555 is 5551793.

It is not a de Polignac number, because 3971555 - 2⁸ = 3971299 is a prime.

It is a super-3 number, since 3×3971555³ (a number of 21 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a d-powerful number, because it can be written as 3¹⁰ + 9³ + 7⁴ + 1 + 5⁵ + 5⁹ + 5⁹ .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 785 + ... + 2925.

It is an arithmetic number, because the mean of its divisors is an integer number (347004).

Almost surely, 2^3971555 is an apocalyptic number.

3971555 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

3971555 is a deficient number, since it is larger than the sum of its proper divisors (1580509).

3971555 is a wasteful number, since it uses less digits than its factorization.

3971555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2206.

The product of its digits is 23625, while the sum is 35.

The square root of 3971555 is about 1992.8760623782. The cubic root of 3971555 is about 158.3629295244.

The spelling of 3971555 in words is "three million, nine hundred seventy-one thousand, five hundred fifty-five".