78209943 has 16 divisors (see below), whose sum is σ = 119421696. Its totient is φ = 44599680.

The previous prime is 78209939. The next prime is 78209953. The reversal of 78209943 is 34990287.

It is not a de Polignac number, because 78209943 - 2² = 78209939 is a prime.

It is a super-2 number, since 2×78209943² = 12233590368126498, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78209895 and 78209904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78209903) 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, 7423 + ... + 14543.

It is an arithmetic number, because the mean of its divisors is an integer number (7463856).

Almost surely, 2^78209943 is an apocalyptic number.

78209943 is a deficient number, since it is larger than the sum of its proper divisors (41211753).

78209943 is a wasteful number, since it uses less digits than its factorization.

78209943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7654.

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 78209943 is about 8843.6385611353. The cubic root of 78209943 is about 427.6488644040.

The spelling of 78209943 in words is "seventy-eight million, two hundred nine thousand, nine hundred forty-three".