7978322477 has 4 divisors (see below), whose sum is σ = 7978625436. Its totient is φ = 7978019520.

The previous prime is 7978322467. The next prime is 7978322489. The reversal of 7978322477 is 7742238797.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7742238797 = 1217 ⋅6361741.

It can be written as a sum of positive squares in 2 ways, for example, as 3287990281 + 4690332196 = 57341^2 + 68486^2 .

It is a cyclic number.

It is not a de Polignac number, because 7978322477 - 2¹⁶ = 7978256941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7978322437) 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, 107774 + ... + 166047.

It is an arithmetic number, because the mean of its divisors is an integer number (1994656359).

Almost surely, 2^7978322477 is an apocalyptic number.

It is an amenable number.

7978322477 is a deficient number, since it is larger than the sum of its proper divisors (302959).

7978322477 is a wasteful number, since it uses less digits than its factorization.

7978322477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302958.

The product of its digits is 8297856, while the sum is 56.

The square root of 7978322477 is about 89321.4558602803. The cubic root of 7978322477 is about 1998.1919056400.

The spelling of 7978322477 in words is "seven billion, nine hundred seventy-eight million, three hundred twenty-two thousand, four hundred seventy-seven".