4015978 has 16 divisors (see below), whose sum is σ = 6599880. Its totient is φ = 1824256.

The previous prime is 4015939. The next prime is 4015981. The reversal of 4015978 is 8795104.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3229209 + 786769 = 1797^2 + 887^2 .

It is a super-2 number, since 2×4015978² = 32256158592968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an Ulam number.

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 7 ways as a sum of consecutive naturals, for example, 1051 + ... + 3022.

Almost surely, 2^4015978 is an apocalyptic number.

4015978 is a deficient number, since it is larger than the sum of its proper divisors (2583902).

4015978 is a wasteful number, since it uses less digits than its factorization.

4015978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4121.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 4015978 is about 2003.9905189396. The cubic root of 4015978 is about 158.9511868407.

The spelling of 4015978 in words is "four million, fifteen thousand, nine hundred seventy-eight".