78551643 has 8 divisors (see below), whose sum is σ = 110248000. Its totient is φ = 49611528.

The previous prime is 78551621. The next prime is 78551657. The reversal of 78551643 is 34615587.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78551643 - 2⁹ = 78551131 is a prime.

It is a super-3 number, since 3×78551643³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78551843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 688993 + ... + 689106.

It is an arithmetic number, because the mean of its divisors is an integer number (13781000).

Almost surely, 2^78551643 is an apocalyptic number.

78551643 is a deficient number, since it is larger than the sum of its proper divisors (31696357).

78551643 is a wasteful number, since it uses less digits than its factorization.

78551643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378121.

The product of its digits is 100800, while the sum is 39.

The square root of 78551643 is about 8862.9364772631. The cubic root of 78551643 is about 428.2707602714.

The spelling of 78551643 in words is "seventy-eight million, five hundred fifty-one thousand, six hundred forty-three".