78145231 has 2 divisors, whose sum is σ = 78145232. Its totient is φ = 78145230.

The previous prime is 78145229. The next prime is 78145253. The reversal of 78145231 is 13254187.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78145231 - 2¹ = 78145229 is a prime.

It is a super-2 number, since 2×78145231² = 12213354256086722, which contains 22 as substring.

Together with 78145229, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 78145193 and 78145202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78145531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39072615 + 39072616.

It is an arithmetic number, because the mean of its divisors is an integer number (39072616).

Almost surely, 2^78145231 is an apocalyptic number.

78145231 is a deficient number, since it is larger than the sum of its proper divisors (1).

78145231 is an equidigital number, since it uses as much as digits as its factorization.

78145231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 31.

The square root of 78145231 is about 8839.9791289346. The cubic root of 78145231 is about 427.5308843093.

The spelling of 78145231 in words is "seventy-eight million, one hundred forty-five thousand, two hundred thirty-one".