7978651 has 4 divisors (see below), whose sum is σ = 8398600. Its totient is φ = 7558704.

The previous prime is 7978639. The next prime is 7978657. The reversal of 7978651 is 1568797.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1568797 = 227 ⋅6911.

It is a cyclic number.

It is not a de Polignac number, because 7978651 - 2¹¹ = 7976603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7978598 and 7978607.

It is not an unprimeable number, because it can be changed into a prime (7978657) 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, 209946 + ... + 209983.

It is an arithmetic number, because the mean of its divisors is an integer number (2099650).

Almost surely, 2^7978651 is an apocalyptic number.

7978651 is a deficient number, since it is larger than the sum of its proper divisors (419949).

7978651 is a wasteful number, since it uses less digits than its factorization.

7978651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419948.

The product of its digits is 105840, while the sum is 43.

The square root of 7978651 is about 2824.6505978616. The cubic root of 7978651 is about 199.8219331747.

The spelling of 7978651 in words is "seven million, nine hundred seventy-eight thousand, six hundred fifty-one".