7978453857 has 16 divisors (see below), whose sum is σ = 12894471360. Its totient is φ = 4835426400.

The previous prime is 7978453841. The next prime is 7978453859. The reversal of 7978453857 is 7583548797.

7978453857 is a `hidden beast` number, since 7 + 97 + 8 + 4 + 538 + 5 + 7 = 666.

It is not a de Polignac number, because 7978453857 - 2⁴ = 7978453841 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7978453794 and 7978453803.

It is not an unprimeable number, because it can be changed into a prime (7978453859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13431444 + ... + 13432037.

It is an arithmetic number, because the mean of its divisors is an integer number (805904460).

Almost surely, 2^7978453857 is an apocalyptic number.

It is an amenable number.

7978453857 is a deficient number, since it is larger than the sum of its proper divisors (4916017503).

7978453857 is a wasteful number, since it uses less digits than its factorization.

7978453857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26863501 (or 26863495 counting only the distinct ones).

The product of its digits is 59270400, while the sum is 63.

The square root of 7978453857 is about 89322.1912908545. The cubic root of 7978453857 is about 1998.2028737356.

The spelling of 7978453857 in words is "seven billion, nine hundred seventy-eight million, four hundred fifty-three thousand, eight hundred fifty-seven".