78043997 has 2 divisors, whose sum is σ = 78043998. Its totient is φ = 78043996.

The previous prime is 78043993. The next prime is 78044003. The reversal of 78043997 is 79934087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71132356 + 6911641 = 8434^2 + 2629^2 .

It is an emirp because it is prime and its reverse (79934087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78043997 - 2² = 78043993 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78043993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39021998 + 39021999.

It is an arithmetic number, because the mean of its divisors is an integer number (39021999).

Almost surely, 2^78043997 is an apocalyptic number.

It is an amenable number.

78043997 is a deficient number, since it is larger than the sum of its proper divisors (1).

78043997 is an equidigital number, since it uses as much as digits as its factorization.

78043997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 78043997 is about 8834.2513548121. The cubic root of 78043997 is about 427.3461881826.

The spelling of 78043997 in words is "seventy-eight million, forty-three thousand, nine hundred ninety-seven".