78399941 has 2 divisors, whose sum is σ = 78399942. Its totient is φ = 78399940.

The previous prime is 78399917. The next prime is 78399953. The reversal of 78399941 is 14999387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78251716 + 148225 = 8846^2 + 385^2 .

It is a cyclic number.

It is not a de Polignac number, because 78399941 - 2⁶ = 78399877 is a prime.

It is a super-2 number, since 2×78399941² = 12293101497606962, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78399941.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78399241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199970 + 39199971.

It is an arithmetic number, because the mean of its divisors is an integer number (39199971).

Almost surely, 2^78399941 is an apocalyptic number.

It is an amenable number.

78399941 is a deficient number, since it is larger than the sum of its proper divisors (1).

78399941 is an equidigital number, since it uses as much as digits as its factorization.

78399941 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 50.

The square root of 78399941 is about 8854.3741167854. The cubic root of 78399941 is about 427.9948848633.

The spelling of 78399941 in words is "seventy-eight million, three hundred ninety-nine thousand, nine hundred forty-one".