78261643 has 2 divisors, whose sum is σ = 78261644. Its totient is φ = 78261642.

The previous prime is 78261607. The next prime is 78261647. The reversal of 78261643 is 34616287.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78261643 is a prime.

It is a super-2 number, since 2×78261643² = 12249769530118898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78261647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39130821 + 39130822.

It is an arithmetic number, because the mean of its divisors is an integer number (39130822).

Almost surely, 2^78261643 is an apocalyptic number.

78261643 is a deficient number, since it is larger than the sum of its proper divisors (1).

78261643 is an equidigital number, since it uses as much as digits as its factorization.

78261643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 37.

The square root of 78261643 is about 8846.5610832685. The cubic root of 78261643 is about 427.7430748308.

The spelling of 78261643 in words is "seventy-eight million, two hundred sixty-one thousand, six hundred forty-three".