78269409 has 15 divisors (see below), whose sum is σ = 117040033. Its totient is φ = 52126524.

The previous prime is 78269381. The next prime is 78269419. The reversal of 78269409 is 90496287.

It is a happy number.

The square root of 78269409 is 8847.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 78269409 - 2²³ = 69880801 is a prime.

It is a super-2 number, since 2×78269409² = 12252200770418562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78269419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 79132 + ... + 80114.

Almost surely, 2^78269409 is an apocalyptic number.

78269409 is the 8847-th square number.

78269409 is the 4424-th centered octagonal number.

It is an amenable number.

78269409 is a deficient number, since it is larger than the sum of its proper divisors (38770624).

78269409 is an frugal number, since it uses more digits than its factorization.

78269409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978 (or 986 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The cubic root of 78269409 is about 427.7572228550.

The spelling of 78269409 in words is "seventy-eight million, two hundred sixty-nine thousand, four hundred nine".