7978042 has 4 divisors (see below), whose sum is σ = 11967066. Its totient is φ = 3989020.

The previous prime is 7978021. The next prime is 7978063. The reversal of 7978042 is 2408797.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (7978021) and next prime (7978063).

It can be written as a sum of positive squares in only one way, i.e., 7834401 + 143641 = 2799^2 + 379^2 .

It is a junction number, because it is equal to n+sod(n) for n = 7977992 and 7978010.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1994509 + ... + 1994512.

Almost surely, 2^7978042 is an apocalyptic number.

7978042 is a deficient number, since it is larger than the sum of its proper divisors (3989024).

7978042 is a wasteful number, since it uses less digits than its factorization.

7978042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3989023.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 7978042 is about 2824.5427948608. The cubic root of 7978042 is about 199.8168489964.

The spelling of 7978042 in words is "seven million, nine hundred seventy-eight thousand, forty-two".