78388373738 has 4 divisors (see below), whose sum is σ = 117582560610. Its totient is φ = 39194186868.

The previous prime is 78388373737. The next prime is 78388373741. The reversal of 78388373738 is 83737388387.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 65416758289 + 12971615449 = 255767^2 + 113893^2 .

It is a super-2 number, since 2×78388373738² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78388373737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19597093433 + ... + 19597093436.

Almost surely, 2^78388373738 is an apocalyptic number.

78388373738 is a deficient number, since it is larger than the sum of its proper divisors (39194186872).

78388373738 is a wasteful number, since it uses less digits than its factorization.

78388373738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39194186871.

The product of its digits is 113799168, while the sum is 65.

The spelling of 78388373738 in words is "seventy-eight billion, three hundred eighty-eight million, three hundred seventy-three thousand, seven hundred thirty-eight".