78215843 has 2 divisors, whose sum is σ = 78215844. Its totient is φ = 78215842.

The previous prime is 78215833. The next prime is 78215873. The reversal of 78215843 is 34851287.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78215843 - 2⁶ = 78215779 is a prime.

It is a super-2 number, since 2×78215843² = 12235436192401298, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78215797 and 78215806.

It is not a weakly prime, because it can be changed into another prime (78215833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39107921 + 39107922.

It is an arithmetic number, because the mean of its divisors is an integer number (39107922).

Almost surely, 2^78215843 is an apocalyptic number.

78215843 is a deficient number, since it is larger than the sum of its proper divisors (1).

78215843 is an equidigital number, since it uses as much as digits as its factorization.

78215843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 38.

The square root of 78215843 is about 8843.9721279525. The cubic root of 78215843 is about 427.6596177889.

The spelling of 78215843 in words is "seventy-eight million, two hundred fifteen thousand, eight hundred forty-three".