78399547 has 2 divisors, whose sum is σ = 78399548. Its totient is φ = 78399546.

The previous prime is 78399473. The next prime is 78399551. The reversal of 78399547 is 74599387.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78399547 is a prime.

It is a super-2 number, since 2×78399547² = 12292977939610418, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78399494 and 78399503.

It is not a weakly prime, because it can be changed into another prime (78399647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199773 + 39199774.

It is an arithmetic number, because the mean of its divisors is an integer number (39199774).

Almost surely, 2^78399547 is an apocalyptic number.

78399547 is a deficient number, since it is larger than the sum of its proper divisors (1).

78399547 is an equidigital number, since it uses as much as digits as its factorization.

78399547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1905120, while the sum is 52.

The square root of 78399547 is about 8854.3518678670. The cubic root of 78399547 is about 427.9941678974.

The spelling of 78399547 in words is "seventy-eight million, three hundred ninety-nine thousand, five hundred forty-seven".