78437923 has 2 divisors, whose sum is σ = 78437924. Its totient is φ = 78437922.

The previous prime is 78437911. The next prime is 78437939. The reversal of 78437923 is 32973487.

It is a weak prime.

It is an emirp because it is prime and its reverse (32973487) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78437923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78437923.

It is not a weakly prime, because it can be changed into another prime (78437903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39218961 + 39218962.

It is an arithmetic number, because the mean of its divisors is an integer number (39218962).

Almost surely, 2^78437923 is an apocalyptic number.

78437923 is a deficient number, since it is larger than the sum of its proper divisors (1).

78437923 is an equidigital number, since it uses as much as digits as its factorization.

78437923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 43.

The square root of 78437923 is about 8856.5186727066. The cubic root of 78437923 is about 428.0639898356.

The spelling of 78437923 in words is "seventy-eight million, four hundred thirty-seven thousand, nine hundred twenty-three".