78815853 has 12 divisors (see below), whose sum is σ = 114002460. Its totient is φ = 52471296.

The previous prime is 78815839. The next prime is 78815897. The reversal of 78815853 is 35851887.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14607684 + 64208169 = 3822^2 + 8013^2 .

It is not a de Polignac number, because 78815853 - 2²¹ = 76718701 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 78815799 and 78815808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78815833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1293 + ... + 12621.

It is an arithmetic number, because the mean of its divisors is an integer number (9500205).

Almost surely, 2^78815853 is an apocalyptic number.

It is an amenable number.

78815853 is a deficient number, since it is larger than the sum of its proper divisors (35186607).

78815853 is a wasteful number, since it uses less digits than its factorization.

78815853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12108 (or 12105 counting only the distinct ones).

The product of its digits is 268800, while the sum is 45.

The square root of 78815853 is about 8877.8292954979. The cubic root of 78815853 is about 428.7503886416.

It can be divided in two parts, 788 and 15853, that added together give a square (16641 = 129²).

The spelling of 78815853 in words is "seventy-eight million, eight hundred fifteen thousand, eight hundred fifty-three".