78408511 has 2 divisors, whose sum is σ = 78408512. Its totient is φ = 78408510.

The previous prime is 78408509. The next prime is 78408521. The reversal of 78408511 is 11580487.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78408511 - 2¹ = 78408509 is a prime.

It is a super-2 number, since 2×78408511² = 12295789194474242, which contains 22 as substring.

Together with 78408509, it forms a pair of twin primes.

It is equal to p_4581970 and since 78408511 and 4581970 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78408521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39204255 + 39204256.

It is an arithmetic number, because the mean of its divisors is an integer number (39204256).

Almost surely, 2^78408511 is an apocalyptic number.

78408511 is a deficient number, since it is larger than the sum of its proper divisors (1).

78408511 is an equidigital number, since it uses as much as digits as its factorization.

78408511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 78408511 is about 8854.8580451637. The cubic root of 78408511 is about 428.0104791885.

Adding to 78408511 its reverse (11580487), we get a palindrome (89988998).

The spelling of 78408511 in words is "seventy-eight million, four hundred eight thousand, five hundred eleven".