78909923 has 4 divisors (see below), whose sum is σ = 79027848. Its totient is φ = 78792000.

The previous prime is 78909893. The next prime is 78909949. The reversal of 78909923 is 32990987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32990987 = 1811 ⋅18217.

It is a cyclic number.

It is not a de Polignac number, because 78909923 - 2¹⁴ = 78893539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78909323) 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, 57953 + ... + 59298.

It is an arithmetic number, because the mean of its divisors is an integer number (19756962).

Almost surely, 2^78909923 is an apocalyptic number.

78909923 is a deficient number, since it is larger than the sum of its proper divisors (117925).

78909923 is a wasteful number, since it uses less digits than its factorization.

78909923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117924.

The product of its (nonzero) digits is 244944, while the sum is 47.

The square root of 78909923 is about 8883.1257449166. The cubic root of 78909923 is about 428.9208979658.

The spelling of 78909923 in words is "seventy-eight million, nine hundred nine thousand, nine hundred twenty-three".