78623689 has 3 divisors (see below), whose sum is σ = 78632557. Its totient is φ = 78614822.

The previous prime is 78623687. The next prime is 78623747. The reversal of 78623689 is 98632687.

The square root of 78623689 is 8867.

It is a perfect power (a square), and thus also a powerful number.

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.

It is not a de Polignac number, because 78623689 - 2¹ = 78623687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78623681) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4434 + ... + 13300.

Almost surely, 2^78623689 is an apocalyptic number.

78623689 is the 8867-th square number.

78623689 is the 4434-th centered octagonal number.

It is an amenable number.

78623689 is a deficient number, since it is larger than the sum of its proper divisors (8868).

78623689 is an frugal number, since it uses more digits than its factorization.

78623689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17734 (or 8867 counting only the distinct ones).

The product of its digits is 870912, while the sum is 49.

The cubic root of 78623689 is about 428.4016540612.

Multiplying 78623689 by its sum of digits (49), we get a square (3852560761 = 62069²).

The spelling of 78623689 in words is "seventy-eight million, six hundred twenty-three thousand, six hundred eighty-nine".