78899831 has 2 divisors, whose sum is σ = 78899832. Its totient is φ = 78899830.

The previous prime is 78899813. The next prime is 78899833. The reversal of 78899831 is 13899887.

Together with previous prime (78899813) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78899831 - 2¹⁴ = 78883447 is a prime.

It is a super-2 number, since 2×78899831² = 12450366663657122, which contains 22 as substring.

Together with 78899833, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78899833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39449915 + 39449916.

It is an arithmetic number, because the mean of its divisors is an integer number (39449916).

Almost surely, 2^78899831 is an apocalyptic number.

78899831 is a deficient number, since it is larger than the sum of its proper divisors (1).

78899831 is an equidigital number, since it uses as much as digits as its factorization.

78899831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 53.

The square root of 78899831 is about 8882.5576834603. The cubic root of 78899831 is about 428.9026119079.

The spelling of 78899831 in words is "seventy-eight million, eight hundred ninety-nine thousand, eight hundred thirty-one".