7878849257 has 8 divisors (see below), whose sum is σ = 8374775976. Its totient is φ = 7386529792.

The previous prime is 7878849247. The next prime is 7878849259. The reversal of 7878849257 is 7529488787.

It can be written as a sum of positive squares in 4 ways, for example, as 3871452841 + 4007396416 = 62221^2 + 63304^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7878849257 - 2¹⁶ = 7878783721 is a prime.

It is a super-2 number, since 2×7878849257² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7878849193 and 7878849202.

It is not an unprimeable number, because it can be changed into a prime (7878849259) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 897308 + ... + 906045.

It is an arithmetic number, because the mean of its divisors is an integer number (1046846997).

Almost surely, 2^7878849257 is an apocalyptic number.

It is an amenable number.

7878849257 is a deficient number, since it is larger than the sum of its proper divisors (495926719).

7878849257 is a wasteful number, since it uses less digits than its factorization.

7878849257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1803627.

The product of its digits is 63221760, while the sum is 65.

The square root of 7878849257 is about 88762.8822030921. The cubic root of 7878849257 is about 1989.8527080532.

The spelling of 7878849257 in words is "seven billion, eight hundred seventy-eight million, eight hundred forty-nine thousand, two hundred fifty-seven".