71578643 has 4 divisors (see below), whose sum is σ = 75345960. Its totient is φ = 67811328.

The previous prime is 71578631. The next prime is 71578651. The reversal of 71578643 is 34687517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34687517 = 41 ⋅846037.

It is a cyclic number.

It is not a de Polignac number, because 71578643 - 2¹⁰ = 71577619 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71578643.

It is not an unprimeable number, because it can be changed into a prime (71578693) 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, 1883630 + ... + 1883667.

It is an arithmetic number, because the mean of its divisors is an integer number (18836490).

Almost surely, 2^71578643 is an apocalyptic number.

71578643 is a deficient number, since it is larger than the sum of its proper divisors (3767317).

71578643 is a wasteful number, since it uses less digits than its factorization.

71578643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3767316.

The product of its digits is 141120, while the sum is 41.

The square root of 71578643 is about 8460.4162427152. The cubic root of 71578643 is about 415.2036412865.

The spelling of 71578643 in words is "seventy-one million, five hundred seventy-eight thousand, six hundred forty-three".