78345971 has 4 divisors (see below), whose sum is σ = 85468344. Its totient is φ = 71223600.

The previous prime is 78345961. The next prime is 78345977. The reversal of 78345971 is 17954387.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78345971 - 2²² = 74151667 is a prime.

It is a super-2 number, since 2×78345971² = 12276182343865682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78345977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3561170 + ... + 3561191.

It is an arithmetic number, because the mean of its divisors is an integer number (21367086).

Almost surely, 2^78345971 is an apocalyptic number.

78345971 is a deficient number, since it is larger than the sum of its proper divisors (7122373).

78345971 is a wasteful number, since it uses less digits than its factorization.

78345971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7122372.

The product of its digits is 211680, while the sum is 44.

The square root of 78345971 is about 8851.3259458682. The cubic root of 78345971 is about 427.8966527046.

The spelling of 78345971 in words is "seventy-eight million, three hundred forty-five thousand, nine hundred seventy-one".