78346809 has 24 divisors (see below), whose sum is σ = 118564992. Its totient is φ = 49758720.

The previous prime is 78346799. The next prime is 78346819. The reversal of 78346809 is 90864387.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78346799) and next prime (78346819).

It is not a de Polignac number, because 78346809 - 2¹⁷ = 78215737 is a prime.

It is a super-2 number, since 2×78346809² = 12276444960964962, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78346819) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63769 + ... + 64985.

It is an arithmetic number, because the mean of its divisors is an integer number (4940208).

Almost surely, 2^78346809 is an apocalyptic number.

It is an amenable number.

78346809 is a deficient number, since it is larger than the sum of its proper divisors (40218183).

78346809 is a wasteful number, since it uses less digits than its factorization.

78346809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1557 (or 1554 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 78346809 is about 8851.3732832821. The cubic root of 78346809 is about 427.8981783143.

The spelling of 78346809 in words is "seventy-eight million, three hundred forty-six thousand, eight hundred nine".