3978515 has 4 divisors (see below), whose sum is σ = 4774224. Its totient is φ = 3182808.

The previous prime is 3978511. The next prime is 3978523. The reversal of 3978515 is 5158793.

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

It is a cyclic number.

It is not a de Polignac number, because 3978515 - 2² = 3978511 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3978511) 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, 397847 + ... + 397856.

It is an arithmetic number, because the mean of its divisors is an integer number (1193556).

Almost surely, 2^3978515 is an apocalyptic number.

3978515 is a deficient number, since it is larger than the sum of its proper divisors (795709).

3978515 is an equidigital number, since it uses as much as digits as its factorization.

3978515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795708.

The product of its digits is 37800, while the sum is 38.

The square root of 3978515 is about 1994.6215179828. The cubic root of 3978515 is about 158.4553838869.

The spelling of 3978515 in words is "three million, nine hundred seventy-eight thousand, five hundred fifteen".