3978591 has 4 divisors (see below), whose sum is σ = 5304792. Its totient is φ = 2652392.

The previous prime is 3978587. The next prime is 3978593. The reversal of 3978591 is 1958793.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1958793 = 3 ⋅652931.

It is a cyclic number.

It is not a de Polignac number, because 3978591 - 2² = 3978587 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978593) 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, 663096 + ... + 663101.

It is an arithmetic number, because the mean of its divisors is an integer number (1326198).

Almost surely, 2^3978591 is an apocalyptic number.

3978591 is a deficient number, since it is larger than the sum of its proper divisors (1326201).

3978591 is a wasteful number, since it uses less digits than its factorization.

3978591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326200.

The product of its digits is 68040, while the sum is 42.

The square root of 3978591 is about 1994.6405691252. The cubic root of 3978591 is about 158.4563928507.

The spelling of 3978591 in words is "three million, nine hundred seventy-eight thousand, five hundred ninety-one".