78350009 has 4 divisors (see below), whose sum is σ = 78367716. Its totient is φ = 78332304.

The previous prime is 78350003. The next prime is 78350023. The reversal of 78350009 is 90005387.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 90005387 = 149 ⋅604063.

It can be written as a sum of positive squares in 2 ways, for example, as 17197609 + 61152400 = 4147^2 + 7820^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78350009 is a prime.

It is a super-2 number, since 2×78350009² = 12277447820600162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78350003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4187 + ... + 13199.

It is an arithmetic number, because the mean of its divisors is an integer number (19591929).

Almost surely, 2^78350009 is an apocalyptic number.

It is an amenable number.

78350009 is a deficient number, since it is larger than the sum of its proper divisors (17707).

78350009 is an equidigital number, since it uses as much as digits as its factorization.

78350009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17706.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 78350009 is about 8851.5540443472. The cubic root of 78350009 is about 427.9040039314.

The spelling of 78350009 in words is "seventy-eight million, three hundred fifty thousand, nine".