78406511 has 2 divisors, whose sum is σ = 78406512. Its totient is φ = 78406510.

The previous prime is 78406487. The next prime is 78406529. The reversal of 78406511 is 11560487.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (11560487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78406511 - 2¹⁰ = 78405487 is a prime.

It is a super-2 number, since 2×78406511² = 12295161934386242, which contains 22 as substring.

It is equal to p_4581860 and since 78406511 and 4581860 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 (78403511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39203255 + 39203256.

It is an arithmetic number, because the mean of its divisors is an integer number (39203256).

Almost surely, 2^78406511 is an apocalyptic number.

78406511 is a deficient number, since it is larger than the sum of its proper divisors (1).

78406511 is an equidigital number, since it uses as much as digits as its factorization.

78406511 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 78406511 is about 8854.7451120854. The cubic root of 78406511 is about 428.0068400077.

Adding to 78406511 its reverse (11560487), we get a palindrome (89966998).

The spelling of 78406511 in words is "seventy-eight million, four hundred six thousand, five hundred eleven".