7978779 has 24 divisors (see below), whose sum is σ = 12046320. Its totient is φ = 5084352.

The previous prime is 7978777. The next prime is 7978781. The reversal of 7978779 is 9778797.

7978779 = T₅₂₂ + T₅₂₃ + ... + T₅₇₄.

It is an interprime number because it is at equal distance from previous prime (7978777) and next prime (7978781).

It is not a de Polignac number, because 7978779 - 2¹ = 7978777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7978771) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20317 + ... + 20705.

It is an arithmetic number, because the mean of its divisors is an integer number (501930).

Almost surely, 2^7978779 is an apocalyptic number.

7978779 is a deficient number, since it is larger than the sum of its proper divisors (4067541).

7978779 is a wasteful number, since it uses less digits than its factorization.

7978779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491 (or 488 counting only the distinct ones).

The product of its digits is 1555848, while the sum is 54.

The square root of 7978779 is about 2824.6732554404. The cubic root of 7978779 is about 199.8230017376.

The spelling of 7978779 in words is "seven million, nine hundred seventy-eight thousand, seven hundred seventy-nine".