78631897 has 2 divisors, whose sum is σ = 78631898. Its totient is φ = 78631896.

The previous prime is 78631853. The next prime is 78631901. The reversal of 78631897 is 79813687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77510416 + 1121481 = 8804^2 + 1059^2 .

It is a cyclic number.

It is not a de Polignac number, because 78631897 - 2²³ = 70243289 is a prime.

It is a super-3 number, since 3×78631897³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78631897.

It is not a weakly prime, because it can be changed into another prime (78631297) 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, 39315948 + 39315949.

It is an arithmetic number, because the mean of its divisors is an integer number (39315949).

Almost surely, 2^78631897 is an apocalyptic number.

It is an amenable number.

78631897 is a deficient number, since it is larger than the sum of its proper divisors (1).

78631897 is an equidigital number, since it uses as much as digits as its factorization.

78631897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 49.

The square root of 78631897 is about 8867.4628276638. The cubic root of 78631897 is about 428.4165613513.

The spelling of 78631897 in words is "seventy-eight million, six hundred thirty-one thousand, eight hundred ninety-seven".