78394905 has 32 divisors (see below), whose sum is σ = 147571200. Its totient is φ = 39350016.

The previous prime is 78394903. The next prime is 78394907. The reversal of 78394905 is 50949387.

It is an interprime number because it is at equal distance from previous prime (78394903) and next prime (78394907).

It is not a de Polignac number, because 78394905 - 2¹ = 78394903 is a prime.

It is a super-2 number, since 2×78394905² = 12291522259918050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78394903) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14785 + ... + 19374.

It is an arithmetic number, because the mean of its divisors is an integer number (4611600).

Almost surely, 2^78394905 is an apocalyptic number.

It is an amenable number.

78394905 is a deficient number, since it is larger than the sum of its proper divisors (69176295).

78394905 is a wasteful number, since it uses less digits than its factorization.

78394905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34190 (or 34184 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 78394905 is about 8854.0897329991. The cubic root of 78394905 is about 427.9857206201.

The spelling of 78394905 in words is "seventy-eight million, three hundred ninety-four thousand, nine hundred five".