78009943 has 4 divisors (see below), whose sum is σ = 85101768. Its totient is φ = 70918120.

The previous prime is 78009941. The next prime is 78009983. The reversal of 78009943 is 34990087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34990087 = 11 ⋅3180917.

It is a cyclic number.

It is not a de Polignac number, because 78009943 - 2¹ = 78009941 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78009896 and 78009905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78009941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3545896 + ... + 3545917.

It is an arithmetic number, because the mean of its divisors is an integer number (21275442).

Almost surely, 2^78009943 is an apocalyptic number.

78009943 is a deficient number, since it is larger than the sum of its proper divisors (7091825).

78009943 is a wasteful number, since it uses less digits than its factorization.

78009943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7091824.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 78009943 is about 8832.3237599173. The cubic root of 78009943 is about 427.2840225460.

The spelling of 78009943 in words is "seventy-eight million, nine thousand, nine hundred forty-three".