78945642 has 48 divisors (see below), whose sum is σ = 177395400. Its totient is φ = 25353216.

The previous prime is 78945641. The next prime is 78945707. The reversal of 78945642 is 24654987.

It is a happy number.

78945642 is a `hidden beast` number, since 7 + 89 + 4 + 564 + 2 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 73977201 + 4968441 = 8601^2 + 2229^2 .

It is not an unprimeable number, because it can be changed into a prime (78945641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74734 + ... + 75782.

Almost surely, 2^78945642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78945642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88697700).

78945642 is an abundant number, since it is smaller than the sum of its proper divisors (98449758).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78945642 is a wasteful number, since it uses less digits than its factorization.

78945642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1207 (or 1204 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 78945642 is about 8885.1360147158. The cubic root of 78945642 is about 428.9856059852.

The spelling of 78945642 in words is "seventy-eight million, nine hundred forty-five thousand, six hundred forty-two".