78215873 has 2 divisors, whose sum is σ = 78215874. Its totient is φ = 78215872.

The previous prime is 78215843. The next prime is 78215881. The reversal of 78215873 is 37851287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47224384 + 30991489 = 6872^2 + 5567^2 .

It is a cyclic number.

It is not a de Polignac number, because 78215873 - 2¹⁶ = 78150337 is a prime.

It is a super-2 number, since 2×78215873² = 12235445578304258, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78215873.

It is not a weakly prime, because it can be changed into another prime (78215833) 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, 39107936 + 39107937.

It is an arithmetic number, because the mean of its divisors is an integer number (39107937).

Almost surely, 2^78215873 is an apocalyptic number.

It is an amenable number.

78215873 is a deficient number, since it is larger than the sum of its proper divisors (1).

78215873 is an equidigital number, since it uses as much as digits as its factorization.

78215873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94080, while the sum is 41.

The square root of 78215873 is about 8843.9738240228. The cubic root of 78215873 is about 427.6596724658.

The spelling of 78215873 in words is "seventy-eight million, two hundred fifteen thousand, eight hundred seventy-three".