3978655 has 16 divisors (see below), whose sum is σ = 5158080. Its totient is φ = 2937088.

The previous prime is 3978643. The next prime is 3978659. The reversal of 3978655 is 5568793.

3978655 = 508² + 509² + ... + 522².

It is a cyclic number.

It is not a de Polignac number, because 3978655 - 2¹¹ = 3976607 is a prime.

It is a d-powerful number, because it can be written as 3¹³ + 9³ + 7⁶ + 8⁵ + 6⁷ + 5³ + 5⁹ .

3978655 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978659) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2739 + ... + 3931.

It is an arithmetic number, because the mean of its divisors is an integer number (322380).

Almost surely, 2^3978655 is an apocalyptic number.

3978655 is a deficient number, since it is larger than the sum of its proper divisors (1179425).

3978655 is a wasteful number, since it uses less digits than its factorization.

3978655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250.

The product of its digits is 226800, while the sum is 43.

The square root of 3978655 is about 1994.6566120513. The cubic root of 3978655 is about 158.4572424944.

The spelling of 3978655 in words is "three million, nine hundred seventy-eight thousand, six hundred fifty-five".