78646397 has 2 divisors, whose sum is σ = 78646398. Its totient is φ = 78646396.

The previous prime is 78646367. The next prime is 78646433. The reversal of 78646397 is 79364687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78039556 + 606841 = 8834^2 + 779^2 .

It is a cyclic number.

It is not a de Polignac number, because 78646397 - 2¹⁰ = 78645373 is a prime.

It is a super-2 number, since 2×78646397² = 12370511522163218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78646307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39323198 + 39323199.

It is an arithmetic number, because the mean of its divisors is an integer number (39323199).

Almost surely, 2^78646397 is an apocalyptic number.

It is an amenable number.

78646397 is a deficient number, since it is larger than the sum of its proper divisors (1).

78646397 is an equidigital number, since it uses as much as digits as its factorization.

78646397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 50.

The square root of 78646397 is about 8868.2803857343. The cubic root of 78646397 is about 428.4428935760.

The spelling of 78646397 in words is "seventy-eight million, six hundred forty-six thousand, three hundred ninety-seven".