78219643 has 2 divisors, whose sum is σ = 78219644. Its totient is φ = 78219642.

The previous prime is 78219613. The next prime is 78219649. The reversal of 78219643 is 34691287.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78219643 - 2⁵ = 78219611 is a prime.

It is a super-2 number, since 2×78219643² = 12236625102094898, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78219596 and 78219605.

It is not a weakly prime, because it can be changed into another prime (78219649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39109821 + 39109822.

It is an arithmetic number, because the mean of its divisors is an integer number (39109822).

Almost surely, 2^78219643 is an apocalyptic number.

78219643 is a deficient number, since it is larger than the sum of its proper divisors (1).

78219643 is an equidigital number, since it uses as much as digits as its factorization.

78219643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 40.

The square root of 78219643 is about 8844.1869609365. The cubic root of 78219643 is about 427.6665434115. Note that the first 3 decimals are identical.

The spelling of 78219643 in words is "seventy-eight million, two hundred nineteen thousand, six hundred forty-three".