78909738 has 16 divisors (see below), whose sum is σ = 158300256. Its totient is φ = 26223120.

The previous prime is 78909737. The next prime is 78909749. The reversal of 78909738 is 83790987.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78909737) 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, 17881 + ... + 21852.

It is an arithmetic number, because the mean of its divisors is an integer number (9893766).

Almost surely, 2^78909738 is an apocalyptic number.

78909738 is an abundant number, since it is smaller than the sum of its proper divisors (79390518).

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

78909738 is a wasteful number, since it uses less digits than its factorization.

78909738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40069.

The product of its (nonzero) digits is 762048, while the sum is 51.

The square root of 78909738 is about 8883.1153319092. The cubic root of 78909738 is about 428.9205627717.

The spelling of 78909738 in words is "seventy-eight million, nine hundred nine thousand, seven hundred thirty-eight".