78251231 has 2 divisors, whose sum is σ = 78251232. Its totient is φ = 78251230.

The previous prime is 78251219. The next prime is 78251233. The reversal of 78251231 is 13215287.

It is a strong prime.

It is an emirp because it is prime and its reverse (13215287) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78251231 is a prime.

It is a super-2 number, since 2×78251231² = 12246510306030722, which contains 22 as substring.

Together with 78251233, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78251194 and 78251203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78251233) 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, 39125615 + 39125616.

It is an arithmetic number, because the mean of its divisors is an integer number (39125616).

Almost surely, 2^78251231 is an apocalyptic number.

78251231 is a deficient number, since it is larger than the sum of its proper divisors (1).

78251231 is an equidigital number, since it uses as much as digits as its factorization.

78251231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 29.

The square root of 78251231 is about 8845.9725864373. The cubic root of 78251231 is about 427.7241048806.

The spelling of 78251231 in words is "seventy-eight million, two hundred fifty-one thousand, two hundred thirty-one".