78643853 has 8 divisors (see below), whose sum is σ = 86141880. Its totient is φ = 71464960.

The previous prime is 78643841. The next prime is 78643879. The reversal of 78643853 is 35834687.

It can be written as a sum of positive squares in 4 ways, for example, as 7038409 + 71605444 = 2653^2 + 8462^2 .

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 78643853 - 2⁸ = 78643597 is a prime.

It is a super-2 number, since 2×78643853² = 12369711229371218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78643813) 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, 79268 + ... + 80253.

It is an arithmetic number, because the mean of its divisors is an integer number (10767735).

Almost surely, 2^78643853 is an apocalyptic number.

It is an amenable number.

78643853 is a deficient number, since it is larger than the sum of its proper divisors (7498027).

78643853 is a wasteful number, since it uses less digits than its factorization.

78643853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159567.

The product of its digits is 483840, while the sum is 44.

The square root of 78643853 is about 8868.1369520323. The cubic root of 78643853 is about 428.4382738667.

The spelling of 78643853 in words is "seventy-eight million, six hundred forty-three thousand, eight hundred fifty-three".