78642923 has 2 divisors, whose sum is σ = 78642924. Its totient is φ = 78642922.

The previous prime is 78642853. The next prime is 78642931. The reversal of 78642923 is 32924687.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78642923 - 2⁸ = 78642667 is a prime.

It is a super-3 number, since 3×78642923³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (78642953) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39321461 + 39321462.

It is an arithmetic number, because the mean of its divisors is an integer number (39321462).

Almost surely, 2^78642923 is an apocalyptic number.

78642923 is a deficient number, since it is larger than the sum of its proper divisors (1).

78642923 is an equidigital number, since it uses as much as digits as its factorization.

78642923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 41.

The square root of 78642923 is about 8868.0845169631. The cubic root of 78642923 is about 428.4365850330.

The spelling of 78642923 in words is "seventy-eight million, six hundred forty-two thousand, nine hundred twenty-three".